Imperfection of market mechanism is the inherent cause of the emergence of business groups in developing countries,and the government economic development policy makes business groups choose diversified strategy.Business groups sharing and holding financial institution and listed company means that they can mobilize more financial resources to diversify their industries.This paper discusses the potential threat of business groups in developing countries to the stability of financial system by George A.Akerlof's looting model,and puts forward relevant policy advices.