The Japanese electoral system had adopted the single non-transferable vote (SNTV). Under SNTV, three to five members were elected from each constituency based on a plurality of votes. However, a series of corruption scandals since 1988 in Japan had damaged confidence in political system. As a result, Diet passed new measures transforming the middle-size district system into a mixed-member system in January 1994, combining single-member district & PR party lists. This article introduces the reform process and the new electoral system. It was the first time that Japanese House of Representatives adopted the single-member district & PR party lists parallel system on October 20, 1996. The article is intended to describe the electoral process and analyze its political consequences The preliminary conclusions of the study are: (1) The new electoral system in Japan is of great advantage to LDP. (2) The new electoral system didn't correct the 'money politics' and transform the electoral competition from candidate-oriented to party and policy-oriented in Japan.