Recently with the development of power switching device and DSP which has perip -heral devices to control AC servo system, the servo technology has met a new development opportunity. In this study, a DSP based AC servo system with a 3-phase PMSM is proposed. The newly produced DSP TMX320F2812 version C which has the performance of fast speed, 150MIPS, and rich peripheral interface is used. Also space vector pulse width modulation (SVPWM) and the digital PI control are implemented to the servo control system.