Latin American countries chose the Presidentialism in the course of modernization. These countries experienced unstable constitutional system for years and also had a difficulty in solidifying democracy. On the contrary European countries of Parliamentarism had built a stable constitutional system. It is true the argument that the Presidentialism is inferior to the parliamentarism has been supported by this fact. In recent days, however, the constitutional government system of Latin American countries is quite well operated with a rapid progress of democracy. Brazil could be a typical example. Braizil is making a remarkable growth of the market economy, mature democracy and regime change between ruling and opposition parties. Therefore the argument for the Parliamentarism based on the historical experience of Latin America is more likely to lose a ground. In the Presidentialism of multiparty country, to discuss how to secure the stability of political situation, how to evaluate the combination of residentialism and Proportional representation and how to manage the political situation when the president doesn’t get enough support of dominant assembly will be more constructive than to simply compare the Presidentialism to the Parliamentarism. And this productive discussion will draw wisdom from the historical experience of Latin America who had been through the political upheaval.