Abstract: The framework of life course policy in the study of Leisering and Leibfried shows that the dynamics of poverty and social policy are correlative. Through the Compartive tire study, The author found that people's life courses are institutionaliz ed by social policies and the social policies in Sweden have stronger institutionalization effect than those of America. Social policies in America have different effects on different classes. The life courses of underclass in the United States are institutionalized deeper than the wealthy. The social policies have changed with the reformation in both of the two countries, but the trand has not changed. The effects of social policies in these two countries are different with Germany in the study of Leiserin g and Leibfried. The conclusion is that the degree and effect of institutionalization of life courses are different with different social policies.