Every country has the right to join international organization. That must be protected and respected by country in the world. Indonesia, as a country based on law, recognizes the TPP as multinational trade agreement. Thus, Indonesia’s awareness of TPP still need to be promoted eagerly that will not be doubted. However, in reality, the result is high-standard for trade and investment across the globe. TPP as a new 21st century agreement as an important step toward the ultimate goal of open trade and regional integration across the region. Through this research, the laws and regulation contents in 30 chapters of the TPP are still need thoroughly study by the government together with every aspects of legal person, business person, and other related aspects in the TPP to do comprehensive study. The purpose of this research is to assess of the merit of TPP for Indonesia. The result of this legal research will show the factors that could be benefits fir Indonesia if Indonesia decided to join TPP and the impact on national development program. Thus, this research may give contribution and input to the government who are keen to join the TPP. TPP weighing potential cost and benefit is no different to other FTAs. Its depend on the markets whether the countries involved need the goods and services as its offered in the markets, whether the capability of the member countries to pay such cost for the goods and services, and also whether the quality of the goods and services are meet the standard quality of the member countries. If Indonesia join TPP right now, Indonesia will need to do a law process which is called accession. Why its accession, why its not ratification? Because TPP has been formed and signed this year as planned by end of March 2018, so Indonesia become a new member of this agreement and Indonesia need to do accession. Ratification is only for the countries who join the agreement from the beginning. TPP will benefit Indonesia if Indonesia has thoroughly conduct comprehensive study of TPP with professionals and regulators, also increase the potential human resources in Indonesia such as conduct the awareness of TPP, and continue educate the people thorough Indonesia archipelagoes. The impact of TPP for Indonesia will be more open to access market, the flexibility to access goods and services because of the free trade, single market access, social and culture also will be discussed because Indonesia through and through follow the culture of the team work as known as “gotong royong” and with the open market will potentially change the people mindset to become more competitive event though we are not a competitive nation from the root itself. As from economic impact, Indonesian economic must increased for both professionals and nations. From legal impact, the law regulators must work hard to comply with all the TPP contents andvi must need a strong negotiator in for some area that need to be protected and still can’t be touch by foreigners. In legal aspect, Indonesia literally will need to tighten and strengthen position and need to change not just several laws but many of laws need to be changed, also the government regulations, etc.