Abstract: Preparation of polypyrrole with special characteristics and micro-morphologies by selecting specific dopants has attracted much attention in recent years. Characteristics and micro-morphologies of polypyrrole influenced by dopants are one of the major research contents. This paper discusses the doping mechanism of polypyrrole are expounded detailedly，and effects of different dopants on the characteristics and micro-morphologies of polypyrrole are introduced systemically.