This paper deals with a software system for the displacement analysis of arbitrary mechanisms, which has been discussed by many researchers.However, concerning the topological analysis of a mechanism and the automated generation of joint information, several problems remain unsolved.We propose more general methods than those previously reported in order to handle spatial constraints involving higher paris by using solid models and to analyze the structure of the mechanism by considering the directions of multiple closed loops.Furthermore, the technique of mathematical programming is applied to the displacement analysis.The practical applicability of the developed system with the methods described in this paper is demonstrated through sevelal example.