Abstract: Socialism with Chinese characteristics originated from the classic socialism that the classic writers conceived and the traditional socialism that Lenin,Stalin and Mao Zedong founded and built,but has Chinese characteristics meanwhile.Its characteristics,based on China's realities,are to stick to fundamental socialism and develop socialist democracy;to abandon pure socialism and develop non-public sectors of the economy;to realize a well- off society in an all-round way and construct a socialist harmonious society.Correctly understanding socialism with Chinese characteristics will help to enrich and develop the theory of socialism with Chinese characteristics,and to enhance the ability to construct a socialist harmonious society.