Abstract: In this paper,spherical coordinate robot is taken as example for studying kinematies,repeatability and linear compensation problems of manipulator.At first,theDH method of kinematics is studied and the singularity of the inverseproblem of kinematics is pointed out.Then,a design method of linear compensator with model following servo system is presented.At last,the resolution and repeatability problemsare illustrated.Simulation and the results of experiment show that linear compensa-tion is appropriate.