Tacit knowledge is the foundation of enterprise core competitive edge .This paper discusses the main implication of enterprise tacit knowledge and ana lyzes the manners and obstacles of tacit knowledge flowing and converting among knowledge subjects of different levels in enterprise internally.And it also anal yzes the manners and obstacles to tacit knowledge flowing and converting in ente rprises internally and externally.The paper establishes a model of enterprise ta cit knowledge flowing and converting.And it also discusses in detail the measure s to accelerate flowing and converting of enterprise tacit knowledge in line wit h the realities of China's enterprises.