Variety improvement plays an important role in improving the yield per unit area of summer maize, but the reasons for the yield difference between modern summer maize varieties are not clear at present. The experiment was conducted at the National Demonstration Center for Crop Varieties in Shanghe. 390 maize varieties approved or to be approved in Huang-Huai-Hai rivers region of China were selected. To explore the yield and resource use efficiency differences of different summer maize varieties and their causes, plant samples were taken at maize maturity stage to determine yield and its components, dry matter accumulation and distribution, nitrogen accumulation, distribution and utilization, and radiation and thermal utilization efficiency of different varieties at maturity stage. There were significant differences in yield among different varieties of summer maize. The direct path coefficients of number of harvested ear, grain number per ear, and 1000-grain weight on yield were 0.57, 1.00, and 0.88, respectively, indicating that the yield difference among varieties were mainly affected by the change of grain number per ear. The accumulation and distribution of dry matter and nitrogen had significant effects on summer maize yield. Compared with that in the yield range of <7 t hm-2, the total dry matter of the plant population in the yield range of 7.0-8.0, 8.0-9.0, 9.0-10.0, 10.0-11.0, and >11.0 t hm-2 was increased by 12.25%, 20.52%, 29.61%, 40.11%, and 54.04%, respectively. Grain nitrogen accumulation was increased by 16.62%, 24.85%, 38.45%, 48.42%, and 68.41%, respectively. Grain dry matter allocation was increased by 5.11%, 9.93%, 13.32%, 15.51%, and 17.94%, and grain nitrogen allocation was increased by 4.09%, 7.24%, 7.37%, 7.31%, and 10.91%, respectively. The radiation use efficiency of grain was increased by 12.50%, 21.25%, 30.00%, 41.25%, and 55.00%, respectively. The thermal utilization efficiency of grain was increased by 11.36%, 20.45%, 29.55%, 39.77%, and 53.41%, respectively. To achieve high-yielding and high-efficient production of summer maize, high-yielding maize varieties were improved dry matter and nitrogen accumulation in maize population, increased the proportion of dry matter and nitrogen distribution in grain, improved the utilization efficiency of nitrogen, radiation and thermal in plant, and promoted the synergistic improvement of yield components, especially the increase of grain number per ear.