In the new century, foods support capability is a hot point of the world, especially by the year 2030 when population of China will reach peak value of 1 6 billion. The whole world focuses on Chinese food self sufficiency and world food market chaos. The population will enter a phase of zero increasing or decreasing after reaching the peak value. Estimated by the national situation analysis group of Chinese Academy of Sciences, in the year 2030, GNP of per capita of China will reach 12 600 USD, which is equal to medium developed countries. According to Chinese meal custom, rational foods consumption of per capita is 460 kg when GNP of per capita of China reaches 12 600 USD in year 2030. In the coming 30 years, China has to provide foods for another 300×106 people. Total foods demand will be 736 000×10 3t, which is 241 823×10 3t more than the food production of 1997, 494 177×10 3t. Rate of population increasing will be 6 5‰ annually while food demand increasing will be 12 1% annually. Without environmental damage and no impact on comparison advantage, potential of farmland production is 660 000×10 3 in year 2030, which is 90% of the total foods demand. Based on food demand per capita respectively 420 kg and 460 kg, and totally 57 96 and 73 60×10 6t, farmland (seeding area) is estimated 114 453×10 3hm 2 and 113 883×10 3hm 2. Unit food production is estimated 4 725 kg and 5 595 kg/hm 2 . Then the total food production will reach 540 8×10 6t and 637 2×10 6t. Therefore, after dynamic changes of the farmland, food supply capacity will be 93% and 87% of the requirements. Food substitution capability of non farmland resources may be as much as 90×10 6t. Countermeasures for foods ensure include guaranteeing foods supply and development. Four aspects should be recognized: policy support to protect farmland, scientific and technological progress and input, conceive of food production system, ensuring system and high efficient hydraulic projects. Establishment of policy to protect farmland will keep dynamic balance of farmland, protect farmland of East China, protect paddy field and topsoil of farmland, and improve farmland quality. Progress and input of sciences and technologies include general decision making techniques, biological techniques and industrialization, agricultural information techniques, increasing productivity of unit farmland, fodder techniques, environmental protection and agricultural disaster reduction techniques. Setting up multi purpose food production and guarantee systems is allocation of multi purpose food production system, allocation of food production bases of China, food ensuring system of China. Implementing high efficiency water conservancy projects for agriculture is saving on water and increasing the efficiency in using water. It is important to establish three systems for water saving, that is, water management system, price system and high efficient technical system. With the analysis of higher food requirement, lower farmland production and non farmland substitution, it is showed that food demand in 2030 will be 736 000 ×10 3t, of which about 90% comes from farmland and 10% comes from non farmland substitution, and food demand and supply of China for the next 30 years is basically in balance. Using the international food resources in little amount to adjust Chinese market will not cause chaos of the international food market.