As the mainstream frame to discuss the boundary of the finn, the theory of specialized assets failed to supply the reasonable account, so it needed new survey. This paper discussed the deficiency of the theory in detail from the assumption of opportunism, production, assets specialization, the nature of transaction cost, uncertainty, and also the discussion unit of transaction. Also in this paper, the case of Fisher Body-General Motors Relationship had been scanned and explained in a new method. It also tried to provide the additional eyeshot for research of the question of firm boundary.