Abstract: Theoretical basis of socialist core values is historical materialism. Marxist values does not deny the value of any individual's subjective side, but opposes the view regarding value as independently generated and maintained by the subjective.Marxism thinks that value is determined by specific social and historical conditions, in particular, the development of material productive forces, the status of production mode and economic relations.Theoretical basis of fundamental values of social democracy is ethical socialism and critical rationalism, whose philosophical foundation is subjective idealism.The core spirit of ethical socialism is to deny historical law of socialism takes the place of capitalism, while the Communist Party persists in historical inevitability that socialism replaces capitalism.Marxist values have distinct class nature, while values of social democracy have characters of superclass and humanization.Core values of socialism have characteristics of people's nature, while values of social democracy have characteristics of citizenship.Differences exist in theoretical basis of the two values.