This study draws upon self-verification theory, social identity theory and self-categorization theory to investigate the dual effects of system design, i.e., identity confirmation (the self) and identification (the community), on virtual community (VC) participation. An important theoretical development is the conceptualization of VC identity and the elucidation of its system design determinants. Community presentation, i.e., system design features for presenting a virtual community identity, is hypothesized to facilitate identification by setting the boundaries for inter-group comparison and highlighting the in-group homogeneity. Furthermore, system design features that prior research identified as determinants for identity confirmation, i.e., self-presentation, deep profiling, and co-presence, are argued to have impacts on identification directly by influencing social comparison and indirectly by making the VC identity attractive. The research model accounts for the dual roles of system design features, i.e., effects on identification and identity confirmation, in explaining VC participation. The implications of these results for both theory and practice are discussed.