Abstract: This article rethinks the relations among state, party and society, adds a structural dimension to traditional political embeddedness analysis, and figures out three components of political embeddedness as government work experience, party member and party organization. A study of 238 community-based NGOs in X city through mixed methods shows that: party members in an NGO will strength the effectiveness；party organization in an NGO will contribute to the effectiveness and formalization and an indirect effect of party organization on effectiveness via formalization. Theoretical and practical implications are discussed, also limitations of this study and suggestions for future studies are provided.

Key words: Party organization, Party-construction, NGO formalization, NGO effectiveness, community-based NGO