Marxist geography is an important school in human geography, but also has a profound influence on other disciplines. David Harvey's Social Justice and the City is the founding work of Marxist geography. This book is highly theoretical and involves many large and complex issues, and thus is also difficult to interpret. Harvey tried to understand and analyze urban(ism) problems from a holistic perspective, and innovated the theory of "social processes-spatial form". By comparing the urban research methodology between liberalism and Marxism, he concluded that the nature of theory arises from the synthesis of methods and philosophy, the nature of space lies in human practices, the nature of justice depends on the operation of the social processes, and the nature of urbanism is the needs and products of capital production. This work created the knowledge foundation of Marxist geography, forged the critical path of urban research, and opened up the growth point of contemporary Marxism. Chinese intellectuals should pay close attention to the uneven urbanism, put forward the "general urban problem" in the new development stage, insist on and strengthen the thoughts research, and make a bold theoretical revolution around contemporary issues through symptomatic reading of different classic theories.