Taiwan and Mongolia are both belong to newly post-Leninist semi-presidential countries. Both countries also are located in Asia, been evaluated as ”free” by Freedom House, and have strong neighbors and democratized at almost the same period. However, these two countries have different government types. First, Mongolia has experienced ”cohabitation” under incongruence of president and parliament, but Taiwan has experienced ”minority government with parliament majority” and ”minority government without parliament majority.” Second, Mongolia has experienced coalition government as ”united majority government” by two major parties while Taiwan has not. This paper tries to explain these two questions by many institutional and non-institutional factors.