This dissertation modifies the model of Yang and Ng (1995) to investigate the condition of the emergence of the firm from a specialized exchange economy. It is assumed in this dissertation that there are fixed costs involved in the operation of a firm. After taking into account of this factor, I re-examine its effects on the division of labor and the structure of firm following Yang and Ng¡¦s framework. The model adopts an inframarginal framework to analyze the subject, in which a firm demonstrates diminishing returns, while both the final labor input and the intermediate labor input demonstrates increasing returns defined upon individuals. However, it is assumed that only the final labor input has the economies of specialization. It is argued in this dissertation that the existence of fixed learning costs may stimulate the economy to undergo structural changes if suitable conditions are met, which are largely related to relative market efficiency between markets.