ABSTBACTThe ceramic gas turbine has high potential as an automotive engine in the future, because of its multifuel capability, good thermal efficiency and low exhaust emissions. The Petroleum Energy Center (PEC) has been developing a 100kW ceramic gas turbine (CGT) under the auspices of MITI in Japan. A 7 year program was started in 1990 and, after the interim target was attained, the program moved to engine testing. At the same time, a study on vehicle applications of CGT has been made in order to make full use of the superiority of CGT from the standpoint of energy usage and protecting the environment. In this study, CGT/BATTERY hybrid systems were investigated, mainly from the standpoint of fuel economy.