Abstract: Gas hydrate is a very important marine energy source in the future. In this paper, we made a brief introduction to the formation, stabilization and distribution of gas hydrate and the present research status and future trend in a global point of view. Emphasis is put on the mandate and results of some world known gas hydrate scientific drilling programs. Research programs, such as ODP164, ODP204, Gulf of Mexico Gas Hydrates Joint Industry Project, Japan Gas Hydrates Drilling Program, India Gas Hydrates Drilling Program and Korea Gas Hydrates Drilling Program, are introduced and described. The occurrence of gas hydrate in the areas of the drilling program remains the major concern of the scientific and industrial societies. It is also the focus of this paper. Besides, exploration techniques and drilling target selection expertise are discussed.