OECD NEA Halden Reactor Project started in 1958, and JAERI has been participated in the Project since 1967 on behalf of Japanese Government. During the participation period, not only JAERI but also many Japanese companies and PNC, which cooperated with JAERI, have carried out many irradiation tests of fuel at HBWR. The fuel irradiation researches in Halden Reactor Project are composed of joint programme which the Halden Project executes by the member`s common consent, and participant programme which the participant executes under bilateral contact between the Halden Project. The committee of the Halden Joint Research Programme was organized by agencies and companies, which jointed the cooperative researches. This report summaries the achievements of the Halden Joint Research Programme on fuel irradiation tests between Jan. 1991 and Dec. 1993, as the Halden Project renews the agreement every three years. The eight cooperative researches have carried out and completed at the end of the period except one. But, the research which have not yet been completed in the period is also included in this report. (author).