Aging is a challenge to global development. This challenge is particularly significant for China because it has the largest elderly population worldwide. The proportion of aging population continues to increase, and solely relying on government efforts to meet the needs of the elderly is inadequate. Hence, involvement of social organizations in elderly care services is needed. Their core members exhibit higher sense of responsibility and identification with the organization than regular members, thus profoundly affecting organizational development. Based on the Social Capital Theory, this study employed a multistage stratified random sampling method to examine the social capital stock of elderly social organizations and their core members across six cities in Anhui Province, China. Chi-square tests analyzed the relationship between the core members' demographic factors and individual performance. Independent-sample t-tests assessed the relationship between social capital and individual performance. Finally, binary logistic regression models determined the factors influencing the individual performance of core members. Social networks within core members' social capital and the internal social capital of elderly caring social organizations (ESOs) affect the individual performance of core members. Therefore, organizations should provide more training opportunities for core members to expand their networks. Cultivating a shared language and vision as components of social capital can enhance organizational cohesion and operational stability.