OBJECTIVE. This study explored factors related to cognition of social capital among Japanese older people. METHOD. Using a cross-sectional survey design, data were gathered from 940 people aged over 65 years. Cognition of social capital was compared by gender, and it was regressed on participation in community activities and health behaviors of middle age and current health status. RESULTS. Men had higher cognitive social capital than women (p = .004). Multiple regression analysis shows that men who rested for health during middle age had high cognition of social capital. Cognition of social capital was also related to self-rated health, depression, and cognitive difficulties for both men and women. Daily activity was included among women. DISCUSSION. Participation in community activities and health behaviors during middle age were associated factors for cognition of social capital among the older people, and encouraging cognition of social capital was important for active aging.