Abstract: Karl Marx's ethical thought,embodied in his views on the purpose of labor,the highest good in life and the measure of social progress,is featured with perfectionism and he points out that human labors exist for two purposes:to satisfy the needs of existence and to realize the essential power,and the realization of the essential power is the super-utilitarian purpose which is higher than the purpose of satisfying the needs of existence.Marx believes that the most important thing for human is self-development,and that the self-perfection and self-realization are the highest goodness in life.They are the good in the sense of perfectionism,and this concept of good is also included in Aristotle's thoughts on perfectionism.Marx regards the free and comprehensive development of individual as the perfection standard of the society,and uses this standard to measure and evaluate the good and evil of each society.The theoretical basis of Marx's criticism of the capitalist system is not a theory of justice,but the perfectionism about the pursuit of human's development.

Key words: Karl Marx, perfectionism, labor, the development of human, self-realization