The issue of socialist theory and practice is a major subject that is exactly in development. Based on the analysis of theoretical explorations made in the practice of Marxist scientific socialism theory in the world scope, the book highlights the innovation of the Marxist scientific socialism theory by socialism with Chinese characteristics, and reflects the unity of the theoretical logic of Marxist scientific socialism and the historical logic of China's social development. In addition, it analyzes the unprecedented new subjects and new tests faced by the Communist Party of China in holding power, and expounds the importance and urgency of strengthening the party's governance ability and governing and holding power for the people. In the study of the theory of socialism with Chinese characteristics and foreign Marxist socialism theories, the book further explores the relationship between capitalism and socialism in the world process, and demonstrates the inevitable historical process and trend of the development of human society in the prospect of the development of world socialism and socialism with Chinese characteristics.