[en] In July, 1987, the Central Research Institute of Electric Power Industry founded the Human Factor Research Center, and it has promoted the research placing emphasis on practical use. In this report, among these subjects, J-HPES which has been developed since 1986 is described. The Japanese version of human performance enhancement system (J-HPES) is the Japanese version of HPES that the Institute of Nuclear Power Operations in USA has developed. It is a series of systems which, on the trouble occurred as human deed took part or became the origin, which are related to the operation and maintenance of nuclear power stations, analyzes and evaluates exactly the whole facts and the cause of the occurrence of such deed, and proposes the effective and concrete countermeasures for preventing troubles. It is shown in the easily usable form of procedure. The basic policy and the targets of the time of developing the Japanese version are shown. The course of development, the whole constitution and the features, and the contents of J-HPES are described. (K.I.)