The National Center for Theoretical Sciences (NCTS) was established on August 1, 1997 by the National Science Council (NSC). The community of theoretical sciences in Taiwan has benefited considerably from NCTS. Starting from January of the year 2004, the NSC decided to expand the NCTS into three parts: keep the one in Hsinchu and add two offices in Taipei and Southern Taiwan. For the two new offices, the Taipei Office (NCTS) is organized by National Taiwan University while the Southern Taiwan Office if jointly organized by National Cheng-Kung University and National Sun Yat-sen University. The objectives of the NCTS are four-fold. 1. The Center aims to be an international center of excellence in theoretical sciences. 2. The Center aims to serve all the theoretical scientists in Taiwan. 3. The Center aims to train talented students and provide a pleasant environment for young researchers to establish themselves. 4. The Center aims to promote interdisciplinary research among theoretical sciences and their applications. The core of NCTS consists of topical programs. The current programs include, but not restricted to, algebraic geometry, arithmetic geometry and number theory, differential geometry, partial differential equations, representation theory, discrete mathematics, applied mathematics. These groups are led by program organizers. To realize the above objectives, NCTS host visiting scholars, short-term or long-term and also NCTS provides several positions of NCTS Scholars, Center Scientists, Post-Doc Fellows and Research Assistants. Proposals for programs are welcome as well.