Property management is the basis for community construction.In community management，property management firm，community neighborhood committee and proprietor committee are the main bodies in community co-governance.The sound interaction among these bodies is the key for community harmony.According to our investigation，the property management firm goes smooth with community neighborhood committee，but tough with proprietor committee.This paper conducts a dialectical analysis of the Contradictions between property management firm and proprietor committee，proposes a sound interaction mechanism between property management and community management on the premise of strengthening institution construction，and further promotes the construction of harmonious communities.