China: Many grounds for invalidation

17 November 2008

Ai-Leen Lim, Hans Lee


In China, while patent infringement suits are usually handled by the People's Intermediate Courts, the determination of the validity or otherwise of a patent is within the exclusive jurisdiction of the State Intellectual Property Office (SIPO). The Patent Re-examination Board (PRB) is the institution within SIPO that is responsible for handling patent invalidation proceedings. In practice, when being sued for patent infringement, it is almost a standard strategic response by an alleged infringer to file an invalidation request with the PRB and to request for a stay of proceedings by the court. Three types of patent are provided for under the Chinese Patent Law:

  1. "invention patent", which is a patent issued after substantive examination and has a maximum term of 20 years from the filing date;
  2. "utility model", which relates to the shape and structure of an article and is issued for a maximum term of 10 years from the filing date upon satisfaction of formality requirements; and
  3. "design patent".

This article focuses on the invalidation procedure in relation to invention patents.

The post-grant patent invalidation procedure was first introduced in China when the Law came into effect in 1985. Patent invalidation proceedings are provided for and governed by Articles 45-47 of the Law and Rules 58-71 of the Implementation Regulations to the Patent Law, both of which came into effect in 2001. The substantive and procedural requirements on patent invalidation proceedings are set out in the Guidelines for Examination, published by SIPO under the authority of Rule 121 of the Implementation Regulations. Since patent invalidation proceedings are litigious in nature, their general conduct, such as evidentiary requirements, is also governed by the Law on Civil Litigation and the Law on Administrative Litigation.


Any person, including the patentee, may file a request for patent invalidation at any time after the grant of the subject patent under one or more of the grounds of invalidation stipulated in Rule 64 of the Regulations. The grounds are generally interpreted with reference to the Guidelines for Examination and may be divided into two broad categories, namely substantive and technical grounds. The substantive grounds are:

  • Non-patentable subject matter. The following are excluded from patent protection: (a) an invention which is contrary to the law, social morality or is detrimental to public interest; (b) an invention which is not a new and improved technical solution to a product or a method; and (c) an invention on scientific discoveries, rules and methods of intellectual activity, methods for diagnosis or treatment of diseases, animal and plant varieties, or substances obtained by nuclear transformation.
  • Lack of novelty, inventiveness, or practical utility. A patent could be invalidated for lack of novelty. Although relative novelty (referring to an invention not having been in use in China and not published anywhere in the world before the priority date) applies in China, it is widely expected that absolute novelty (referring to an invention not having been used or published anywhere in the world before the priority date) will be required after the third amendment to the Law comes into effect, which is expected in late 2009.

A patent could also be attacked for invalidation if it is not inventive, that is it does not possess an outstanding substantive characteristic and notable improvement over the state-of-the-art. In practice, a three-step test is adopted during invalidation proceedings: (a) ascertaining the closest prior art, (b) identifying whether there are any differences between invention and the closest prior art, and (c) determining whether any differences are obvious to persons skilled in the art.

There are six technical grounds:

  1. Added subject matter.
  2. Insufficient disclosure of description.
  3. Claim lacking support.
  4. Claim lacking clarity and/or succinctness.
  5. Claim lacking an essential technical feature.
  6. Double patenting.


A request to invalidate a patent begins with the filing of a petition in writing with the PRB. The petition should include the grounds of invalidity and supporting evidence (where appropriate). The petitioner may file supplemental grounds and evidence within one month from the date of filing of the petition. If the PRB is satisfied that the petition meets all formality requirements, the PRB will forward the petition and all relevant documents to the patentee, usually within weeks but sometimes this can take several months.

The patentee will have one month after receiving the petitioner's documents from the PRB to file a response together with their evidence. The patentee's response and supporting evidence will then be forwarded to the petitioner, who has an option to file a further response in reply within one month of the receipt of the patentee's response.

The case will be set down for oral hearings at the PRB in Beijing, upon request by the parties, after the deadline for the petitioner's response has passed. Oral hearings are open to the public and will be presided over by a panel consisting of three to five, but usually three, members who are examiners with the appropriate technical background. At the end of the oral hearings, the panel will ask one or both parties to submit supplemental responses, which are usually filed within one week of the hearing. An oral hearing session typically takes no more than one day.

Although a patentee can amend claims of the patent during invalidation proceedings, the scope of these amendments is severely restricted under the prevalent SIPO practices. Accordingly, only amendments to delete claims, to combine claims, or to delete alternative features of a claim are allowed, provided that there is no broadening of the original claims after amendment.


When preparing for patent invalidation proceedings in China, the priority of a petitioner would be to identify the appropriate grounds of invalidity. Among the various grounds, an attack on the lack of novelty and/or inventiveness, and added subject matter would probably have the most weight, especially given the very limited scope of allowable amendments during invalidation proceedings. As the patentee has very limited flexibility to make amendments to the patent under the prevalent SIPO practices, it is of utmost importance that the patentee provides clear, logical and persuasive rebuttals and evidence in advance to the PRB in order to convince the PRB otherwise. Although many forms of evidence are accepted by the PRB, documentary evidence with an unambiguous publication date would be the most reliable for invalidation proceedings. A party can adduce expert evidence and be represented by a lawyer or patent attorney in patent invalidation proceedings.


It would usually take the PRB several months to deliver a decision on patent validity, and the decision would be one of (a) patent totally invalidated, (b) patent partially invalidated, or (c) patent valid. The PRB does not have the authority to request amendments to the claims, nor would the PRB suggest possible amendments to rescue a patent.


A total of 10,455 invalidation proceedings covering patents, utility models and designs were filed between 2003 and 2007. In 2007 alone, there were 354 petitions for patent invalidation and the trend shows a slight drop compared with previous years. There are no official statistics on the success rate of patent invalidation requests but an unofficial estimate suggests that about 50% to 60% of the petitions are successful.


Any party may make an appeal to the First Intermediate People's Court of Beijing against a decision rendered by the PRB within three months of the receipt of the decision by way of judicial review, and the decision of the First Intermediate Court is further appealable to the Higher People's Court of Beijing within 15 days (30 days for a foreign party) upon receipt of the judgment of the Intermediate People's Court. An appeal against the PRB's decision could be based on legal, evidentiary or procedural grounds and the Court will review the PRB's decision de novo. Unofficial statistics suggest that the reversal rate of PRB's decision is relatively low – less than 20%.


The patent invalidation system in China is generally perceived to be working well and the quality of the PRB has always been well regarded. A major problem in the system, however, is the unduly restrictive scope of amendments available to the patentee during invalidation proceedings. This restriction makes a Chinese patent more vulnerable when exposed to a validity attack compared to the position of a counterpart US or European patent, and has the effect of invalidating a patent on a valuable invention due to a technicality.

Therefore, it is strongly recommended that this restrictive approach should be relaxed, for example, by allowing more forms of amendments during invalidation proceedings to make the Chinese patent system more compatible with the national policy to promote the development of science and technology, especially when the patents have gone through substantive examination by SIPO.