At the crossing of centuries, it is very important to review the main problems and research in theoretical physics. This was the purpose of the International Workshop on Frontiers of Theoretical Physics, allowing the interchange of ideas among people with different expertise. The proceedings can be divided into two parts: (1) general view talks about string, particle physics, nuclear physics, etc. given by Profs. T Yoneya, M Kobayazhi, A Sanda, Z Li and F Sakata; (2) research related to many important fields, such as quantum field theory, string theory, particle physics, condensed matter physics, nuclear physics and mathematical physics. Contents: Aspects of Current Particle Physics (M Kobayashi); CP Violation Past, Present and Future (A I Sanda); Nonlinear Science in Nuclear Physics (F Sakata); String Theory OCo Where are We Now? (T Yoneya); The Descent Equation of Noncommutative Differential Geometry on Lattice (K Wu); Supersymmetry for Flavors (C Liu); Quantization on Manifolds and Induced Gauge Potentials (Y Ohnuki); Chiral Lagrangian in QCD (Q Wang & Z-M Wang); and other papers. Readership: Graduate students and researchers in theoretical physics."