Abstract EN:

Endowed with a parliamentary system, nowadays most of the democratic countries accepted a reinforcement of the executif power, especially the responsibility of the government to the parliament. Thailand, known as a "democratic" country, practices the parliamentary system. However the democracy of this country is always interrupted by the military. This situation appeared when the political parties are ineffectual to manage the politic because of theirs divisions. Consequently the politic and the democracy of this country are unsteady. They are always in the "vicious cercle", called by the technocrats. The government depends on the strong political group in each time. The prime minister is considered to be the most important and the most powerful person among the ministers. He is the first among the others. Indeed the mechanisms of the constitution and the laws allow him to have much more power and to carry out the administration of the state. He is in possession of the extensive power. Consequently he becomes "the strong chief executive" of the state. Nevertheless owing to the changing of the politic, the pressure of the division among the ministers and the influence of the military, he sometimes becomes politic mediator rather than the chief executive by the reason of keeping his stability. This research concerns the evolution, the choiceness, the nomination and the power of the prime minister of thailand. These different points are linked by the political events which explain how the prime minister obtains this post, how he carries out the administration of the state and for what reason he is sometimes in the control of some powerful groups.