JAERI has carried out the R&D on hydrogen production system using high-temperature nuclear heat supplied from HTGR to progress in the utilization of nuclear energy without CO_2 emissions. Some technologies required from the viewpoint of economy, controllability and safety should be developed and demonstrated to commercialize the HTGR hydrogen production system. JAERI has constructed a 30-MWt HTGR, named HTTR, of which first criticality was attained in 1998. A hydrogen production system by means of a steam reforming of nature gas is planned as the first nuclear heat utilization system coupling with HTTR as a demonstration test facility. Prior to coupling of the steam reforming system with the HTTR, an out-of-pile test, which is an approximately 1/30 scale system of the HTTR steam reforming system and simulates key components downstream from an intermediate heat exchanger, is under construction to confirm safety, controllability and performance of the HTTR steam reforming system. This report describes the development items and the demonstration test program for the HTGR hydrogen production system.