In this paper, the models for the resource potential of photosynthesis and light-temperature of corn, rice and soybean, climate-soil resources potentials in the northeast region of China were esteablished by using the new functions that the crops yield response on temperature, water and soil resources, the geographic distribution of the potentials were analysed, too. Also, the maximum crops yield increase potential were analysed in improving and exploitting the water, thermal, soil resources conditions and agro-tech utilization. The result showed that the light, light-temperature, climate and resource potential productivity of the main crops are high in every area of northeast region and their geographic difference are quite marked. In the main areas of the northeast region, the main crops potential productivity of photosynthesis are 4-5 times that the actural mean crops yield, the light-temperature potentials are about 21,000 kg per ha, it is about 3. 5 times as large as the actural yield, the climate potential productitvty of corn and rice are about 17000 kg per ha, the soybean is 5,000kg per ha, and they are about 2.8 times that the actural yields. The resource potentials of corn and rice are about 12,000kg per ha, that of soybean is 3,500kg per ha, and they are about 2.0 times that the actural yields. The climate yield in the south area of the northeast region are about 2. 5 times that of the north. The exploitation and utilizable potentials of the resources and agro-tech are great, the crops yield could increase by 40-60 percent with improving the thermal condition in the north and east areas, it could increase by 40 percent with building irrigation work in the southwest and the Sanjiang Plain areas, it could increase by 40 percent with improving the soil ecological condition. The resource, climate and light-temperature potential productitvity of main crops are realizable progressively with making great effort.