The Third Plenary Session of the 16th Central Committee of the Communist Party of China points out that the shareholding system is the main form to realize public ownership. This is an impor- tant theoretical breakthrough and breaks the traditional idea that shareholding system is capitalism and is not the understanding of the system in dogmatism and finds the realization form which connects public ownership with market economy and restores and develops the ownership theory of Marxism. This paper expounds the importance of public ownership realization form theory.