How to Search CNIPA Patents in English

To search Chinese patents in English, start with a publication number when you have one. Otherwise, search a recorded applicant name or a few technical keywords, then narrow the results to China. English titles, abstracts and translations can help you identify documents; the original Chinese publication remains the reference for the wording you are investigating.

This guide walks through Patent Task's Chinese patent search, with CATL and BYD documents as concrete examples. Patent Task is an independent third-party service, not the China National Intellectual Property Administration (CNIPA). If you need the government system, use the official entry points listed below.

Choose your starting point

What you have	Where to start	What to enter or inspect
A Chinese publication number	Patent search → Advanced Filters → Patent Number	The complete identifier, such as CN114497826B
A company or applicant name	Patent search → Advanced Filters → Applicant	A name recorded on a patent, such as Contemporary Amperex Technology Co Ltd
An applicant name recorded on a publication	Chinese patent search → Applicant	Search that name and inspect spelling variants in the results
A technology question	Patent search	A few technical terms, followed by a deliberate country or classification filter
A company research question	Chinese patent search	Combine recorded applicant names with a technical question and inspect the returned documents

The CATL and BYD examples below are linked to their public source documents. They illustrate identifiers and search preparation; they are not a report of searches executed for this article.

How to search a Chinese patent by publication number

A complete publication number is the most direct starting point for a known document. In Patent Task, use the Patent Number field rather than treating the number as a technical keyword:

1. Open patent search. On a small screen, open Filters to reveal the filter panel.
2. Under Search Scope, set Jurisdiction to China · CN.
3. Expand Advanced Filters and enter the full publication identifier in Patent Number, for example CN114497826B.
4. Leave unrelated keyword, applicant and date restrictions empty, then select Apply.
5. If a matching record is available, open it and compare the publication number, title, applicant and dates with your source.

Here are two documented examples you can use to understand the fields:

Publication identifier	Application number	Recorded applicant	Reading topic
CN114497826B	CN202210401809.X	Contemporary Amperex Technology Co Ltd	Water-cooling plate structures that accommodate cooling and cell expansion
CN112787048B	CN202010032553.0	BYD Co Ltd	Battery compartments and passages used during electrolyte filling and formation

The CATL example's source document and BYD example's source document are linked for inspection. The topic descriptions above are editorial summaries of Chinese publications, not official English titles or claim translations.

What if I have an application number instead?

An application number identifies the application; a publication identifier identifies a particular published version. Keep both in your notes. If you only have an application number, use the corresponding field in the official search or examination-information service to locate its publications, then use the resulting publication number in Patent Task's Patent Number filter.

Retain the complete identifier, including the kind code when present. An A publication and a B grant publication should not be assumed to contain identical claims. A grant kind code identifies the document version; it does not establish that the patent remains in force today. When copying from a PDF, check spaces, digits and the final characters against the source.

How to search by applicant or company name

Use the Applicant filter when the question is who filed the documents. A company brand is a useful starting clue, but the recorded legal name is usually a better research input.

1. Find an applicant name on a relevant source document. For example, the selected CATL documents record Contemporary Amperex Technology Co Ltd; the selected BYD documents record BYD Co Ltd.
2. Open patent search, select China · CN, and expand Advanced Filters.
3. Enter one name in Applicant. Leave the main keyword query empty if you want to start with the applicant alone, then select Apply.
4. Inspect the names on the returned documents. Collect relevant Chinese names, English variants, previous names and subsidiary names as separate candidates.
5. Add Publication Date or IPC Code only when it helps answer a defined question. The date filter concerns publication, not necessarily the date the application was filed.

For records already in the platform library, choose that data source and use the Applicant filter. Inspect the recorded names on individual results. A name match is not an automatically consolidated corporate group, and results reflect the coverage of the selected source.

Example: researching CATL or BYD battery patents

The CATL source publication concerns cooling-plate structures. The BYD source publication concerns battery compartments and passages. Use a relevant document to obtain its publication identifier and recorded applicant name, then expand your search around the specific technical problem.

For example, a researcher interested in battery cooling can start with the CATL water-cooling plate sample and inspect its terminology and classifications before searching related designs. Someone researching electrolyte filling can start with the BYD compartmented-battery sample. These are starting documents, not rankings of the companies' most important patents.

Before comparing company totals, record the queried names, publication window and source coverage. Retrieved results do not by themselves represent complete global portfolios or all currently owned patents. A parent company, subsidiary, brand and current rights holder are different research categories; similar names alone do not justify merging them.

How to search Chinese patents with English keywords

Use English to form a technical question, then refine it using the language in relevant documents. A practical sequence is:

1. Open patent search, select China · CN under Jurisdiction, and choose Apply. On a small screen, open Filters first.
2. Enter a small set of concepts in the main search box and select Search. For a battery-cooling question, battery cooling plate is a possible starting phrase. If you change the country or other filters after searching, select Apply to update the results.
3. Read the result titles and abstracts that are available. Where a translated query is displayed, check that it preserves your intended concept.
4. Record useful Chinese terms from relevant sources. For the cooling example, 水冷板 (water-cooling plate) and 电芯膨胀 (cell expansion) are candidate terms to investigate separately or in combination.
5. Try useful synonyms and IPC codes taken from relevant documents. Compare what each change adds or removes before narrowing further.

These phrases are examples of query preparation, not executed searches or evidence of completeness. English-language coverage varies by source and record. A database may provide an English abstract without English claims, and the same Boolean expression may behave differently across search services. Record the expression you actually used.

For a search of records already indexed by Patent Task, choose Platform patent library under Data Source. To query EPO's available Chinese records, keep China · CN, select EPO official, and choose Apply. Selecting China alone does not promise a search of every source. Source-status and partial-result notices matter: if a source is unavailable or a result set is incomplete, keep that limitation with your research notes. A missing result can reflect coverage, terminology or a restrictive filter rather than the absence of a relevant patent.

For a broader method of developing concepts and synonyms, use the patent search fundamentals guide.

Where are the official CNIPA search tools?

The CNIPA official website links to separate services for searching, publications and procedural records. These entry points were checked on September 23, 2026; the editorial update to this guide does not represent a new verification of the official services.

• Patent Search and Analysis System — 专利检索及分析系统: official search portal, linked from the official homepage as “专利检索”. Start here when locating technical documents in the official system.
• Patent Publications — 专利公布公告: publication portal. Use the relevant identifier to locate published material.
• Patent Examination Information Inquiry — 专利审查信息查询: examination-information portal. Use the appropriate application record for procedural information.

Follow each service's current access and authentication instructions. The availability of a public entry page does not establish that every function works without an account or supports English queries. If an address changes, return to CNIPA's official homepage. Our explanation of CNIPA and its responsibilities distinguishes the administration from third-party search services.

Check the document version, family and legal status

Once you have relevant documents, separate three follow-up questions:

• Which text am I reading? Confirm the publication identifier and kind code. Check claims, paragraphs, drawings and numerical conditions against the intended document version.
• Which related applications matter? Follow priority and family information across the territories relevant to your question. A US grant does not mean a Chinese family member has the same claims, and one member's lapse does not establish that the entire family is inactive.
• What is the dated status? Check the responsible office's records and relevant events. Record the search date and any data-update date shown, rather than relying solely on a result label.

Chinese Patent Law Article 34 concerns publication of invention applications and permits earlier publication on request. That rule should not be applied indiscriminately to every patent type. Article 44 addresses certain early termination events. Publication, grant and current rights status are separate questions.

For a US patentability project, a Chinese publication may be relevant prior-art material to evaluate. Its relevance still depends on its disclosure, dates and the rules applicable to the project. A freedom-to-operate assessment asks a different question: it also requires the relevant territory, current rights and a comparison between claims and the proposed product or process.

Keep a useful search record

Save enough information to reproduce your work and return to the evidence:

Purpose and date: The technical or legal question, intended territory and search date.

Database and query: The service, exact terms, applicant names, country, classifications and date filters used.

Document: Publication and application numbers, title, applicant, publication date and source URL.

Relevant evidence: Claim, paragraph or figure references, plus the feature being compared.

Open questions: Missing translations, collection gaps, document versions and status checks still needed.

The search log template can help organize this record. When moving into drafting, keep your invention's distinguishing features separate from what the source documents disclose. The patent drafting workspace supports new US, EP and JP drafts from your own disclosure. It does not currently create CN drafts; use Chinese sources as research references and keep the target filing requirements separate. Use the Chinese drafting requirements guide when preparing for that filing route, or the patent drawing tool and drawing preparation guide when you need figures explaining your own components and their relationships.

Common questions about searching CNIPA patents in English

Can I read Chinese patent claims in English?

Where a source provides a translation, it can help you navigate and understand the document. Verify important technical terms, negation, relationships, numerical limits and formulas against the original Chinese publication. An English abstract is not a translation of all claims, and an English-language family member is not automatically equivalent claim text.

Is CNIPA patent search free?

Access conditions depend on the service and function. Check the official portal's current requirements and, for Patent Task, the pricing and access conditions. Access to a search page does not necessarily include unrestricted full text, bulk downloads, exports or analysis.

Why does an English applicant search miss a company I know?

The source may record a Chinese name, an abbreviated English name, a previous name or a subsidiary instead of the familiar brand. Start from a known document, copy its recorded applicant and test relevant variants separately. Use the Applicant filter with each verified name and inspect the source documents before combining results.

Does an empty result mean there are no relevant patents?

No. Check the identifier, remove unnecessary filters and try alternative terminology. Unpublished applications and gaps in language or source coverage can also affect results. Preserve those limits in the search record instead of treating a zero-result screen as a novelty or clearance conclusion.

Start a Chinese patent search, or begin with the source-linked CATL and BYD documents to build a focused research question.