Abstract: The aim of this study is to investigate the temporal and spatial distribution characteristics of roots of super-high-yield summer maize by comparing root characteristics of different summer maize cultivars. High-yield cultivar, Denghai661(DH661), and normal-yield cultivar, Zhengdan958 (ZD958), were selected as material. The differences in temporal and spatial distribution characteristics of roots of the two cultivars in fields were studied using the soil profile sampling method. The results show that the dry root weight, TTC reducing capacity, TTC reducing quantity, absorbing area and active absorbing area of DH661 are all significantly higher (P0.05) than those of ZD958 through the whole growth stages, and after the tasseling, the proportion of the dry root weight of DH661 are significantly higher (P0.05) than that of ZD958 in the deep soil (60200 cm). These results indicate that more water and nutrients are absorbed and transported by roots of super-high-yield DH661 which has the domination in root spacing distribution, number of roots in deeper layers, the effective touching area with soil and root activity at the later growth stages. As for DH661, it has a larger root system and stronger root function. The larger root system can increase root activity, deep root distribution and promote larger shoot development. All in all, because of the root characteristics, the DH661 can uptake more water and nutrients from the soil, promote the shoot growth well and supply the abundant filling matter. Therefore, DH661 can gain higher yield because it has a better root system.