During the War of Resistance against Japanese Aggression period, Wang Yanan worked in the Political Department of the Military Commission of the National Government chaired by Zhou Enlai for some time. Until liberation, he was employed as a professor of economics at Sun Yat-sen University, director of the Economic Research Institute of Fujian Research Institute and a professor at Xiamen University, engaged in teaching and writing.

From 65438 to 0950, Wang Yanan served as the president of Xiamen University until his death. He is a deputy to the first, second and third sessions of the National People's Congress, a member of the Department of Philosophy and Social Sciences of China Academy of Sciences, and vice chairman of the Fujian Provincial Political Consultative Conference. From 65438 to 0969, he died of cancer in Shanghai at the age of 69, leaving 4 1 works (translations) and more than 340 academic papers.

When Xiamen University held a conference and academic seminar to commemorate the centenary of Wang Yanan's birth, the famous economist Yu Guangyuan summarized Wang Yanan's two great achievements: "First, he translated Das Kapital and used it as a weapon to study China;" Second, it has made great contributions to the cause of Xiamen University. " At the burial ceremony of his ashes, the Fujian Provincial Party Committee called him "a famous economist who is tireless, daring to climb and knowledgeable, and an educator who is loyal to the Party's educational cause". "

Unlike ordinary translators, a book is finished after translation. Wang Yanan took the viewpoint of Das Kapital and Marx's position and method as his weapon to study China's economy and society. For example, China's On Economy (renamed China's Semi-feudal and Semi-colonial Economic Form after liberation), one of his representative works of economic theory system, started with commodity economy with the systematic category of Das Kapital, revealing the economic attributes of commodity form in old China. After the book was published, it was praised as "the capital of China" by academic circles and translated into many languages.

1943, Joseph Needham, a famous British scholar, visited Wang Yanan and asked him about the feudal bureaucracy in China. The two discussed the problem in depth. A few years later, he wrote "Research on Bureaucracy in China", which strongly demonstrated the role of bureaucracy as a superstructure in China's feudal mode of production and economic formation, and pointed out the hope of transforming China and reforming the government.

Wang Yanan devoted his life to the study of economics. In his works, he creatively applied the basic principles of Marxism to study the history and present situation of China, advocated the establishment of "China Economics" and opposed the application of ready-made formulas in theory and practice. It has made important contributions to the application and development of Marxist economics in China.