Since the molecular pump was developed, it is nearly for a century. At the primary stage, it advanced slowly. Before 1970 its applications were in the fields of nuclear physics, electro-vacuum, surface science etc. In the near 20 years, this pump is attached importance, due to the development of semi-conductor, thin-film industry. Now it was developed greatly, it is upto the practical and popular stage. In this paper, the history of the molecular pump is introduced; The conditions in the various stages of the pump are given in detail; On the primary molecular pump, turbomolecular pump, magnetic and gas static bearing type of turbomolecular pump, compound molecular pump, low temp. type of turbomolecular pump, new type of molecular drag pump, ceramic turbomolecular pump, turbomolecular pump to evacuate the reactant and EHV(Extreme High Vacuum) turbomolecular pump, the analyses are emphatically given. At late,the prospect of the pump is described.