This two-volume set constitutes the revised selected papers of the 18th CCF Conference on Computer Supported Cooperative Work and Social Computing, ChineseCSCW 2023 held in Harbin, China, in August 2023. The 54 full papers and 28 short papers presented in these proceedings were carefully reviewed and selected from 221 submissions. The papers are organized in the following topical sections: Social Media and Online Communities; Collaborative Mechanisms, Models, Approaches, Algorithms and Systems; Crowd Intelligence and Crowd Cooperative Computing; Cooperative Evolutionary Computation and Human-like Intelligent Collaboration; Domain-Specific Collaborative Applications.