Tsiwen Law was born in Norwalk, Connecticut. Both his father and maternal grandfather immigrated to the United States from China, although neither became U.S. citizens. Law currently resides in Philadelphia, and is a trial attorney and associate of the law firm of Hwang #38; Associates, P.C. He also teaches courses on Asian American studies, on a part-time basis, at the University of Pennsylvania and Temple University. Law is perhaps most visible in the Philadelphia community through his work with various Asian American organizations, such as the Pan Asian Association, the National Asian Pacific American Bar Association, and the Mayor's Asian American Advisory Board.

Mayor Wilson Goode organized the Mayor's Asian American Advisory Board in the fall of 1988. Thirteen Asian Americans, including Tsiwen Law, were appointed to the board, but only after several years of demands by Philadelphia's Asian American community for greater input in formulating city policy and representation in the city government. The first meeting of the board was held on October 14, and was followed by regular bi-monthly meetings with representatives of different city departments, commissions, and agencies, including a monthly meeting with the Mayor.

At the time of the board's first meeting there were approximately 100,000-150,000 Asian Americans living in Philadelphia, with significant numbers residing in West Philadelphia, South Philadelphia, Olney, Logan, and Center City. The board's general objectives were to serve as a liaison between the city government and the community, promote ethnic cooperation, and protect Asian Americans from discrimination. Specifically, the board provided services for battered women, interpreters for recent immigrants, medical and legal referrals, and served as a resource for recent Asian immigrants. The board also held numerous meetings with the Philadelphia police department to discuss the lack of police protection, police abuses, and disregard for Asian American civil rights.

In November 2001, Law was awarded the Northeast region Trail Blazer Award by the National Asian Pacific American Bar Association (NAPABA) for his work with the Asian American community. In addition to recognizing the contributions already mentioned above, Law was honored for being one of the founding members of the NAPABA, chair of the Philadelphia Commission on Asian American Affairs, governor of the Pennsylvania Bar Association and for "over 30 years of unwavering respect to the Asian Pacific American community."