After the referendum，Thailand promulgated the Constitution of B.E. 2550 in August 2007，which is the 18^th constitution since the 1932 Revolution. In contrasting with the Constitution of B.E. 2540，the author points out that，there may be four aspects of influence of the new Constitution in political transformation in Thailand：Promoting the formation of the multi-party system；Giving the opposition in the House of Representatives more power to inspect the government；Giving the people more opportunities to participate in the decision-making process of state policies；Reforming the Senate，and enhancing the leading position of the judicial departmentin Constitutional Organizations.