Abstract: Standardization will play a positive role in regulating the construction, management, operation, maintenance, service, and evaluation of socialized agricultural services. It will guide and promote the sustainable development of socialized agricultural services. The paper discusses the great importance of constructing China's socialized agricultural service standard system from the perspective of standardization, analyzes the content of service and objects of standardization including agricultural material supply services, agricultural production services, agricultural extension services, animal and plant disease control services, circulation services of agricultural products, quality control services to agricultural products, agriculture information services, agricultural financial services, agricultural management and marketing services, etc. The paper proposes the principles of constructing the socialized agricultural service standard system, clarifies the structural elements of the system from dimensions of content of services, links of services and service industries, and plots basic framework of standard system. It also explores the thoughts of promoting the construction and implementation of China's socialized agricultural service standard system such as strengthening top-level design, carrying out pilot work, conducting pre-research and improving talents training.