In July 1987, the National Science Fundation of China approved to support a great project: "Ba- sic Study on W-Band Theory and Technology" , in which about 140 Chinese researchers from Southeast Uni- versity, Chinhua University, Huazhong University, Nanjing Electronic Devices Institute and the Institute of Shanghai Metallurgy Technology were engaged. This project was successfully completed in 1991. Professors Li Sifan (To our great sorrow he died last year) and He Liquan are the chief organizers and directors of this proj- ect. In this paper, an overview of recent advances on W-band theory and technology is presented. It involves electromagnetic analysis and numerical methods, solid state sources, low noise mixers, integrated controlling circuits, six-ports reflectometer, antennas and CAD pakages .