Abstract: Although it is difficult for surgical robot to have full dexterous workspace, surgical robot must have high dexterity orienting to minimally invas ive surgery. Firstly, according to the practical requirement of surgery, quadran t segmentation principle was proposed. The surgical workspace was divided into 8 quadrants, so the dexterous workspace occupied only eighth workspace. And then, the analysis relation was derived between dexterous workspace and workspace of surgical robot. The workspace area of surgical robot could be obtained from the analysis relation, and then the kinematics parameters of surgical robot could be confirmed. Finally, kinematics parameters of the self-defined surgical robot w e re optimized. Therefore, this principle decreases the demand on dexterity of sur gical robot and resolves the conflict between structure and dexterity of robot.