Abstract: Self-servowriting is a good method which deals with servo information writing. This paper analyzed the characteristic of servo model.It shows that position precision is the most important criterion to the validity of self-servowriting.In the paper three different controllers were designed to centrol the self-servowriting process. The esperiment data shows the impoertance of position precision in self-servowriting.This paper indicated the robust controller can resist outer disturbance and provide the position precision in self-servowriting process.

Key words: Servo information, Self-servowriting, Position precision, Robust controller