It has become an urgent task in China to develop modern agricultural sciences and technologies for supporting food security since the establishment of the national food policy. Based on the clarification of the concept of food security and distinguishing human being food from animal feed, the future supply potential and deficit of agricultural products from the existed cultivated and non-cultivated land resources were estimated. It was indicated that the arable land should be used mainly for human being cereal production while the animal feed could be produced from some cultivated land, grassland and sea or ocean area. Then the major scientific and technological problems to be resolved for securing the food production in China were put forward, including the science and technology in arable land expansion, improvement and replacement, those in efficient sustainable utilization of the cultivated land and those in coping with the abiotic stresses, as well as the corresponding top-level blue print design of the future research essentials. It was noticed that the interactive development strategy between the advanced agricultural science and technology innovation and the conventional industry technology improvement should be emphasized as a priority. Furthermore, the strategy and policy for the reform of the organization system and management mechanism in the government management of science and technology were suggested, including the establishment of permanent center for sustainable food production monitoring and decision making, the differential responsibilities for ministry of agriculture and ministry of science and technology, the top level blue print design of the science and technology development in agriculture, the science and technology innovation recognized after benefiting the agro-production, and so for.