CPTPP (Comprehensive and Progressive Agreement for Trans-Pacific Partnership) is a trade agreement across the Americas and Asia. It evolved from TPP led by the United States, and now by Japan. There are 11 members with over five hundred million population, and it combined economic account for 13% of world GDP. 20% of Taiwan's trade value came from CPTPP members. In this article, issues of difference among members, the basic requirements for applying CPTPP, problems might occur if Taiwan joins CPTPP and reason why mainland China wants to be part of it, will be discussed.