Abstract: At present, western utilitarianism draws the attention of the academic circles again. Seeing some coherence between utilitarianism and Chinese market economy, some people believe that utilitarianism should be the dominant ethical value in Chinese market economy. This article shows it's unreasonable and will cause confusion in the practice. Present at the beginning and the middle age of capitalism, this ethical value contains a lot of inevitable intern contradictions. They are the contradictions between the maximum of individual benefit and maximum of social benefit, objective criterion and subjective experience, individualism and altrusiom. Especially, there are conflicts of utilitarianism and socialistic economic foundation. Although some of its reasonable factors can be critically absorbed, utilitarianism should not become the fundamental ethical value of our present society.