An expert system, which is one section of Artificial Intelligence, has been discussed and developed in many fields. In statistics, expert system for statistical analysis has also been discussed and some statistical expert systems have been developed. But those systems do not have necessarily enough functions for acquiring knowledge and explaining the process of inference. Moreover we must develop statistical programs according to the framework of those expert systems. In order to solve these problems we have developed statistical expert system STATEX. STATEX separates knowledge base from inference engine and has the functions supporting the acquisition of knowledge and explaining the process of inference. STATEX manages the knowledge in conventional statistical programs and automatically generates statistical programs.