Abstract: To build a socialist harmonious society, the principle of social equity must be embodied, and different understanding to social equity will result in different social policies. In the theories of social equity in western countries, Rawls's theory of justice, Amartya·sen' s theory of capacity and Utilitarianism' s theory of the maximized welfare are representative. Through comparison and analysis between them, some points of view can help China better understand and deal with social equity problems.