This study investigates the redistributive effect of social security reform in urban China using the nationally representative urban household surveys of 1995 and 2002. The main findings are as follows. First, public pension is the main income for the elderly in urban China. The majority of people aged 60 and over (72% in 1995 and 82% in 2002) receive a pension. Second, the social security system in urban China has increased the income of low-income and older age groups and reduced the relative poverty rate. However, the redistributive effect did not offset the expanding income inequality, which resulted in the Gini coefficient of redistributed income in 2002 being higher than that in 1995. Third, during 1995 and 2002, both low-income and high-income groups received a positive net benefit from the social security system, but the net benefit increased with income. The Chinese social security system lacks progressivity in contribution, and does not favor the poor in terms of benefits. Fourth, assuming that the reformed policy was applied to public sector employees, the long-term redistributive effect of the pension system for the working population, calculated using their lifetime income, is larger. (JEL D31, H55, I38)