According to Rule 51 of Implementing Regulations of Chinese Patent Law, when a request for substantive examination is made, and when, within the time limit of three months after the receipt of the notification that the application has entered into substantive examination, the applicant for a patent for invention may amend the application for a patent for invention on its or his own initiative; and within two months from the date of filing, the applicant for a patent for utility model or design may amend the application for a patent for utility model or design on its or his own initiative.

Rule 51 regulates the opportunity for amendment on applicant’s own initiative (also referred as voluntary amendment).  With regard to voluntary amendment on the regulated time, the examiner shall examine whether or not the amendment is in conformity with the provisions of Article 33.

According to Article 33 of Chinese Patent Law, an applicant may amend his or its application for a patent, but the amendment to the application for a patent for invention or utility model may not go beyond the scope of disclosure contained in the initial description and claims.  

If the amendment goes beyond the scope described in the initial description and claims, the examiner shall issue an Office Action to notify the applicant that the amendment is not in conformity with the provisions of Article 33.  In other words, the amendment shall generally be literally described in the original claims and description (including drawings) or can be directly deduced there from the contents literally described in the initial description and claims and the drawings of the description.  The scope described in the initial description and claims submitted by the applicant on the date of filing shall be taken as the basis of examining whether the above-mentioned amendment is in conformity with the provisions of Article 33.

Therefore, in case that the voluntary amendment made by the applicant does not go beyond the scope of the initial description and claims, the applicant may use this chance to make substantive amendments to the document of the application for a patent for invention or utility model.  

In practice, taking good advantage of the opportunity for voluntary amendment may help the applicant for a better protection. Hereafter, several kind of voluntary amendments are illustrated for reference:

-  To seek for a globally consistent patent layout

With the increasing focus on the IP protection strategy, most enterprises strengthen their patent applications to more and more countries, and a globally consistent patent layout is desired so as to achieve convenient and efficient monitor and management.  Generally the examinations for the applicant’s family patent applications are examined at different stages, especially the priority application(s) may be firstly examined or granted among all these family applications.  By virtue of the opportunity for voluntary amendment, the applicant may amend the claims of the corresponding Chinese patent application document in line with the claims of the family applications in other countries, which have been allowed or tend to be allowed.  This is also especially recommended considering that the examination procedures in different countries are now available for all the examiners’ reference.

-  To smooth the substantive examination

The filing date of an application is critical to the applicant since it defines how to determine the prior art when considering the patentability of the application. All the applicants desires to file his application as early as possible, and thus there is often no sufficient time to trim or modify the application in accordance with different regulations under different countries’ patent law before filing.  With the opportunity for voluntary amendment, things will be changed.  The applicant may make amendment to eliminate the formality defects appearing in the description and claims in advance, which is advantageous for smoothing the substantive examination later, and the examination will then be directly focused on the novelty and inventiveness.

-  To polish and perfect the patent application before examination

Similar to the above mentioned, when any rush filing is concerned, the opportunity for voluntary amendment is significantly important for the applicant to polish his invention.  The applicant may take use of the opportunity for voluntary amendment to add some contents in the originally filed application, for example by further defined dependent claims regarding some critical features, or even by further defined independent claims regarding some technical solutions, based on a much more comprehensive consideration and understanding on the whole invention.  Still, this is typically used in a rush filing for a divisional application.  The applicant may file such divisional application(s) firstly before the deadline with the original claims and description for the parent application, and then draft a set of suitably defined claims and file such claims at the opportunity for voluntary amendment.

It is worthy to be stressed here, in particular, the applicant may make voluntary amendment to the application document several times within the above-mentioned regulated time limit and the amendment made at the last time shall be taken as the basis for examination.

Therefore, in order to protect the benefit of the applicant, the applicant may amend the application document, specifically the claims, to obtain a desired and suitable protect scope by using the opportunity for voluntary amendment in case that the amendment does not go beyond the scope of the initial description and claims.