With regard to the growing problem during intergenerational transition of family business,based on a view of Ownership control,the article explores deeply into the growing course of Mitsui Zaibatsu from its origination to formation.The study shows that Mitsui was benefited from the effective problems-solving of 3 levels of Ownership control: to realize “the separation of  family regardless of industry” by “total ownership system”,to ensure Mitsui's healthy development even in fund shortage; to implant the checking-and-balancing concept of Ownership control into the ownership allotment among family members so that the enterprises management risks because of probable “private profit” excessively serious or “shortsighted running” of family leaders are  restrained; the relationship coordination between family owner and Professional Managers is guaranteed by the establishment of “bigcom” based on full empowerment belief and “family governance structure”.A revelation could be gotten that the innovation of ownership control is the effective solution to the problems of the belonging and allotment of Ownership of family enterprises,the structure of ownership and the agent problem because of the division of two kinds of rights.However,many other tasks such as the belief mechanism building between family enterprise and Professional Managers are still to be faced with in theory.