The R&D for tritium technology and studies of tritium science in Japan has been carried out in the national institutions (JAERI, PNC and others), in the universities, and in industry. In fusion fuel technology, the technological R&D of tritium processing and handling has been carried out by TPL-JAERI, including collaboration with TSTA (USA) and basic and innovative research conducted by the universities. PNC has conducted R&D and engineering studies in the heavy water quality control system for FUGEN reactor, a heavy water cooled reactor ATR, and in the tritium recovery system for the heavy water coolant. Since the last meeting at Toronto, there are many developments in the above researches which will be summarized here with some results.