The Seventh National Congress of Communist Party of China is the last and the most important representative meeting of CPC in the democratic revolution period. The localization of Marxism in China is a long-term historical development process. The examination of the Seventh National Congress of CPC in the history of the localization of Marxism in China shows that the Seventh National Congress of CPC signifies the maturity of the main part and the first theoretical fruits of the localization of Marxism in China and is an important link in the development of Marxism in China.