A high expectation is placed on the introduction of Clean Energy Vehicle (CEV) to reduce CO2 emissions and energy consumption in the automotive sector. However, each CEV has its pros and cons. Therefore, the type and the number of CEV need to be considered before considering the way of introducing CEV. Many studies have been done on this topic, but their portfolios leave trucks and buses out of consideration. Also, past studies took energy security and infrastructure cost out of consideration. This study presents new optimization model which obtains optimal CEV portfolio of passenger car, truck, and bus in Japan, considering economy, CO2 emissions, and energy security. Simulation indicates that HEV, NGV, EV in passenger car and NGV, DHV in truck should be introduced, and especially NGV in truck is required in order to achieve the oil dependency rate designed by the government.