Building a diversified food supply system is an important measure to ensure national food security and build an agricultural powerhouse. General Secretary Xi Jinping emphasized that "under the premise of protecting the ecological environment, we should expand from arable land resources to the entire national land resources, from traditional crops and livestock resources to richer biological resources, from forests, grasslands, rivers, lakes and seas for food, from plants, animals and microorganisms for heat and protein, and develop food sources through multiple channels. The No. 1 central document of the Central Government issued a few days ago also made arrangements for this, proposing to "practice the concept of big agriculture and big food, and develop food resources in an all-round way". Overall, building a diversified food supply system requires a global perspective, guided by food consumption demand, optimizing the allocation of agricultural resource elements, and expanding agricultural production space and food supply sources. Establish a big food concept. To build a diversified food supply system, it is necessary to change the understanding of food categories and promote the expansion of food structure from grains, soybeans, and potatoes to oil, sugar, meat, eggs, milk, fruits, vegetables, and aquatic products. Over the past 40 years, the food consumption structure of Chinese residents has shown significant changes: the proportion of staple foods in consumption has decreased, while the proportion of consumption of products such as meat, eggs, milk, fruits and vegetables has significantly increased. In 2024, the Engel coefficient of Chinese residents will decrease to 29.8%, meeting the wealth standard set by the United Nations. The structure of residents' food consumption will continue to upgrade, accelerating the transition from being fully fed to eating well, nutritious, and healthy. Therefore, expanding food sources requires efforts from both the supply and demand sides. On the supply side, continuously improve the comprehensive efficiency and competitiveness of agriculture, enhance food yield and quality, deeply implement the National Nutrition Plan, and encourage enterprises to develop nutritious and healthy food. On the demand side, carry out popularization and promotion of food nutrition and healthy consumption, guide residents to have a scientifically balanced diet, reduce oil and increase beans, increase poultry and milk, and increase consumption of fruits, vegetables, aquatic products, and whole grains. Fully tap into the potential of agricultural production. The construction of a diversified food supply system cannot be separated from the full development of various agricultural resources. It is necessary to promote the coordination of grain, economy, and feed, as well as the development of agriculture, forestry, animal husbandry, and fishery, in order to promote a wider range of food sources and more diverse varieties. This is an important focus to solve the problem of China's total grain production and the structural contradiction between supply and demand in the future, and to meet the demand for more quantity, higher quality, and diverse food consumption of residents. From the perspective of the characteristics of China's total grain supply, the country's grain output has achieved continuous growth for many years, but it cannot keep up with the rapid growth of demand, resulting in a gap between production and demand. From the perspective of the structural characteristics of grain supply and demand, the growth of residents' consumption of animal protein has driven an increase in demand for feed grains. However, China has surplus food and a production and demand gap for feed grains, which is highly dependent on imports to make up for. Therefore, to build a diversified food supply system, in addition to actively developing the planting industry and consolidating and improving comprehensive production capacity, it is also necessary to vigorously develop the forage industry, deep-sea aquaculture, economic forests, and agroforestry, promote the construction of the entire food industry chain, and ensure the safe supply of important agricultural products such as food and meat, eggs, dairy, and aquatic products that provide animal protein. Expand the space for agricultural production. Based on the basic national conditions of countrymen, which has more people and less land, only by expanding food sources from cultivated land resources to the whole land resources, developing food resources in an all-round way and through multiple ways, and realizing the production layout matching the carrying capacity of resources and environment, can we break the constraints of traditional cultivated land scarcity on building a diversified food system. On the one hand, we need to establish a comprehensive farmland protection system that integrates quantity, quality, and ecology. Implement the clear tasks of protecting arable land and permanent basic farmland in the new round of national spatial planning, and build qualified permanent basic farmland into high standard farmland suitable for cultivation, drought and flood protection, high and stable yield, improve the accuracy of farmland restoration and management, and protect the farmland ecosystem. On the other hand, actively developing and utilizing non-traditional arable land resources. Adhere to the combination of "planting according to the land" and "planting according to the land" to develop saline alkali land with agricultural utilization prospects, further explore the production potential of fruits, vegetables, and animal husbandry products in forest land, grassland, and garden land, and expand the production space of aquatic products in natural lakes and deep seas. Emphasize the research and application of modern agricultural technology. Technological innovation is the core element for developing new quality productivity in agriculture. Currently, China's overall agricultural technology innovation has entered the forefront of the world, with a contribution rate of over 63% to agricultural technological progress. A new round of agricultural scientific and technological revolution characterized by biotechnology and information technology is pregnant with a major breakthrough. Computer, Internet, artificial intelligence and other technologies have been accelerated to be applied to agricultural production, greatly improving agricultural total factor productivity. Modern technology is needed to promote the transformation of traditional agriculture to modern agriculture and assist in the construction of a diversified food supply system. Accelerate the promotion of cutting-edge technological innovation and application in the seed industry, form a virtuous cycle of mutual promotion between research and development and market application, guide seed industry technological innovation with market demand, accelerate the cultivation of breakthrough new varieties, and grasp the initiative of seed industry development. Accelerate the research and development of high-precision agricultural machinery and its key components, and promote large-scale high-power machinery suitable for flat areas and small-scale agricultural machinery suitable for hilly areas according to local conditions. Ensure the reduction and substitution of chemical fertilizers and pesticides, and promote soil testing and formula fertilization. Through big data and cloud computing, achieve intelligent irrigation and water conservation, precise fertilization, and integrated water and fertilizer control. Make good use of international resources and markets. In recent years, while the production of grain and important agricultural products has increased, China has gradually become an important importer of agricultural products in the world. With the growth of residents' income and the upgrading of consumption structure, the demand for food and important agricultural products is still growing, and the domestic resource and environmental carrying capacity cannot meet all food production needs. Therefore, while ensuring basic self-sufficiency in grains and absolute food security, building a diversified food supply system requires coordinating domestic agricultural production and agricultural product imports, appropriately importing high-quality foreign agricultural products, and adjusting and supplementing the domestic food production and demand gap. We need to deeply implement the diversification strategy of agricultural product imports, stabilize agricultural product trade cooperation, ensure the stability of import sources, continuously strengthen investment in key links of the agricultural product supply chain, and optimize the layout of the entire industrial chain of imported agricultural products. Accelerate the pace of agriculture going global, focus on cultivating multinational agricultural enterprise groups, build a full industry chain from the source of agricultural inputs and agrochemicals industry chain to processing, logistics, ports, markets, and trade, and enhance the collaborative capabilities of global agricultural resource allocation and other businesses. Author: Han Yang (Director and Researcher of the Fourth Research Office of the Rural Economy Research Department of the Development Research Center of the State Council)