Exchange, as the start of economic research, is one of the important aspects of China’s experience in 40-year reform and opening up. Based on Marx’s materialist conception of history, it is necessary to analyze its reality and theory in historic progress. According to Marx’s definition of exchange, we put forward the concept of exchange relations as: the economic relations between different subjects in the process of exchanging products or labor in the market. Meanwhile, we refine its characteristics in four dimensions as: marketization of subject, diversification of object, virtualization of carrier, and disparity of interests, which exert strong influences over China’s social economy.　　Based on the above and following Marxism political economy tradition, we incorporate these characteristics into the mechanisms of productivity and production relations to summarize China’s evolution path. Firstly, we clarify the decisive role of productivity to exchange relations from the technological perspective: （1） technological progress is the most direct driving force to improve productivity; （2） the ability to master technology is the core of labor; （3） the new labor division patterns spur technology transformation. Since reform and opening up, attention from China’s successive leaders has led to technological continuous progress and rapid improvement of productivity, which produce changes in the subject, object and carrier of exchange relations.Then, we discuss the promote effect of production relations to exchange relations from the benefit perspective: （1） the ownership of the means of production, as the core content of production relations, determines the essence of exchange relations; （2） people’s status and relationship in production reflect exchange relations and reproduce it; （3） the form of product distribution determines the harmony degree of the means of consumption in exchange relations. Since reform and opening up, China has transformed in two aspects: from the ownership by the whole people to the multi-ownership with public ownership as the main body, and from the single distribution form to a diversified distribution form. These transformations lead to diversified social interest and income disparity, thereby complicating the means of consumption in exchange relations.　　In the new era of socialism with Chinese characteristics, it is necessary to take some actions to enable exchange relations to work for people’s growing needs for better life, including making full use of the leading role of science and technology, improving the scientific and cultural level vigorously, building harmonious labor relations in the new era, strengthening supervision and legislation in the field of virtual economy, having confidence in the reform and opening up policy, and exerting the " two roles” to solve the " two failures”.