After the Opium War in 1840, China gradually became a semi-colonial and semi-feudal society, and the national crisis became increasingly severe. From Lin Zexu to Sun Yat-sen, countless people with lofty ideals explored the path of saving the nation from extinction. After repeated failures, under the influence of the October Revolution in Russia, Chinese advanced people grasped the doctrine of Marxism and founded the CPC in 1921. From then on, China’s democratic revolution against imperialism and feudalism was led by proletariat rather than by bourgeoisie. After the victory of the revolution, a people’s democratic dictatorship led by the proletariat would be established, and its development direction would be socialism rather than capitalism. The founding of the People’s Republic of China in 1949 marked the victory of the new democratic revolution in the Chinese mainland, cleared the three mountains in the way of Chinese path to modernization, and established the people’s regime led by the CPC, thus providing the basic social conditions for the realization of Chinese path to modernization. The founding of PRC also marked the beginning of the socialist modernization led by the CPC.