The Urban Management Reform of Guangzhou launched in 2008 have drawn extensive attention.Some discussion of this change reflects not only the public version of the urban management，but also the motivation and determination of Government in making this change.In the context of the above，this paper attempts to explore the dilemma faced by urban management in the relationship between pluralistic principal-agent relationships through a comprehensive survey on the law enforcement situation of Urban Management of Guangzhou.This paper points out the multi-level and multi-objective relations between principals and agents in urban management.The public，government and urban management form the multilayer of principal-agent relationship.In such a multi-principal-agent relationship under which the upstream agents will often abandon the urban management，causing the public distrust and the public stigma of urban management.With rapid economic development，a large number of social problems along have been transferred to the urban management by principal-agent relationships.Finally，this article proposes to change the management philosophy of urban management with the “service” instead of “law enforcement”，solving the dilemma of urban management in the transformation period，in order to achieve the goal of “harmonious society”.