Abstract: Feng Youlan’s Marxist thought runs through his whole academic career. Before the founding of the People’s Republic of China, Feng Youlan had absorbed and learned from the individual views of historical materialism. Afterwards, Feng Youlan accepted Marxism under the leadership of the Communist Party of China. At the same time, he put forward some understanding and thoughts on the On Practice, and actively disseminated and propagated Marxism in international academic activities. As Feng Youlan entered the later years of his life, his Marxist thought rose to a new height. In his later years, Feng Youlan put forward some innovative understandings of Marxist philosophy and used Marxist philosophy as a guide to write New History of Chinese Philosophy. The development of Feng Youlan’s Marxist thought and Feng Youlan’s attempt to integrate Marxist philosophy with traditional Chinese philosophy also provide two enlightenments, namely, the scientific truthfulness of Marxism and the fact that China’s excellent traditional culture should be organically integrated into Marxism.