Is social insurance is positively related to household’s investment in stock and other risky financial asset market? This paper establishes a two-period model of households and finds that the probability and ratio of household’s investment in risky asset increases with participating social insurance，and that this relation is more significant in households with more uncertainty and of risk-love． Using provincial level and 2011 CHFS data，our empirical results prove the theoretical findings． These findings are valuable to China’s social insur-ance mechanism and capital market．