Abstract: This paper presents an algorithm for workspace calculation of a general robot,i.e.a robot with any structure & any degrees of freedom,etc.This alogorithm trans-forms the problem to obtain extreme distances,boundary curves and boundary surfaces of the workspace into a problem to obtain the maximum and minimum values of some objective functions under certain conditions.With different objective functions and co-nstraints properly chosen,aseries of points on the boundary surface of the workspace of a robot can be obtained.