The present volume contains selected papers from the 12th Grinding and Machining Conference, held in China (GMC 2003). Volume is indexed by Thomson Reuters CPCI-S (WoS). This collection presents a selection of over 250 papers, submitted to the conference by many universities and industrial concerns. All of the papers were subjected to peer-review by at least two expert referees. Moreover, fifteen papers on high-speed machining were specially selected by Dr. Ning He, a full professor at Nanjing University of Aeronautics and Astronautics (NUAA), from papers submitted to the International Conference on High Speed Machining, which is organized by the NUAA and will be held in Nanjing from March 31st to April 2nd, 2004. These papers have been selected for the present volume because of their quality and the fact that they cover the main topics of the conference.