As of March 1 2012, IP offices that signed Patent Prosecution Highway (PPH) with the China IPO are as follows:

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The rapid increase of patent application in China makes international cooperation a necessity. This rapid increase in China is closely related to its state policies: the “12th five-year plan outline” proposed to raise the number of patent inventions up to at least 3.3 cases per million population.  With above said, China needs to reach 430,000 cases for its population of 1.3 billion. (Statistics shown only 230,000 cases by the end of 2010).

We see the number of patent application filed in China are growing continuously, in 2010 China was ranked the second largest country in the number of patent applications. The U.S. has more applications than China, but China outraced Japan.  There are still considerable hidden troubles in patent development in China, among the problems they have, the biggest one is having few patent applications filed in other countriesnd its low approval rates.

According to the statistical data in 2010, the total amount of invention patent application filed from China to EPO, JPO, KIPO and USPTO is 10,605 cases, only occupying 1.02% of those of these four major IPOs; whereas during the same period, the total number of invention patent application filed by applicants of the EU member states, Japan, Korea and the United States are 27,735; 33,882; 7,178 and 25,280 cases respectively, occupying correspondingly 7.1%, 8.7%, 1.8% and 6.5% of the total invention patent applications in China.

With the continuous increase of the number of patent application in China, the international cooperation of this patent power state has been extended gradually from trilateral IPOs (JPO, USPTO and EPO), quadrilateral IPOs (JPO, USPTO, EPO, and KIPO) to pentalateral IPOs (JPO, USPTO, EPO, KIPO and SIPO).

In a "IP5" conference held in Guangxi, China in April 2010, directors of the five major IPOs agreed to and emphasized the importance of sharing works, and confirmed the roles allocation for the 10 foundation projects of the IP5: EPO is responsible for a common references data library and a commonly used mix classification; JPO is responsible for the common application forms and the utilization of search and examination results; KIPO is responsible for training policies and a common machine translation system; SIPO is responsible for the rules for statistical factors and quality control, as well as  the  examination and statistical parameters system; USPTO is responsible for the sharing and recording of search policies, and a common search and examination auxiliary utility.