Population aging has become one of the most prominent population trends in China and worldwide. Given the retirement and physical limitation of the elderly, the neighborhood has gradually become the center of their daily lives and communication. Community cohesion plays an essential role in improving the elderly’s subjective wellbeing. However, most present studies on the concept and relationship between different dimensions of community cohesion are mainly in western countries. Meanwhile, most of the studies on the relationship between community cohesion and subjective wellbeing only focused on one aspect of community cohesion such as community interaction. To address this research gap, this study sampled 20 communities in Guangzhou, conducted a questionnaire survey on 969 elderly people, and explored the relationship between four aspects of community cohesion (community interaction, environmental satisfaction, belonging, and participation) and their associations with subjective wellbeing using the Structural Equation Model (SEM). In addition, we performed multi-group analysis to study the association differences among older individuals in communities with different socioeconomic types. We found that: (1) The conceptual relationship between different aspects of community cohesion among older adults is significant; (2) Community environmental satisfaction, interaction, and belonging associate with the elderly’s subjective wellbeing, whereas there is no significant association between community participation and subjective wellbeing; (3) Mental health is an important mediating factor connecting community cohesion and subjective wellbeing, whereas physical health is not. (4) The association pattern of older adults in communities with different socio-economic status are identical, whereas the association strengths are different. In high Socio-Economic Status Index (SESI) communities (communities where older adults with relatively high socioeconomic attributes gather, such as high income and education level), community belonging and participation are significantly associated with community environmental satisfaction and interaction, respectively. In low SESI communities (communities in which older adults with relatively low socioeconomic attributes gather, such as low income and education level), community interaction, belonging, and participation considerably link to community environmental satisfaction, interaction, and belonging, respectively. Regarding the association between community cohesion and subjective wellbeing, community interaction has stronger linkage with the elderly’s subjective wellbeing of in high-SESI aging community than low-SESI aging community. While community environmental satisfaction has stronger association with the elderly’s subjective wellbeing of the elderly in low-SESI aging community than high-SESI aging community. Therefore, it is sensible for community planning to focus on community environment improvement and vibrant community activities organization.