Abstract: The information of 821 common maize varieties approved by Inner Mongolia from 2002 to 2021 was collected, and their yield and main characters were comprehensively analyzed. The results showed that from 2002 to 2021, the yield, number of rows per ear, bulk density, and crude starch content of newly approved maize varieties showed an overall increasing trend. However, the ear diameter, ear length, number of grains per row, 100-grain weight, crude protein, crude fat, and lysine content showed a downward trend. Through correlation analysis, the direct positive effect of plant height on yield was the highest, reaching a highly significant level. Grey correlation analysis showed that plant height was the most important trait affecting maize yield. When selecting high-yield maize hybrid varieties, while ensuring overall excellent disease and insect resistance, attention should be paid to selecting varieties with suitable plant height and ear position, and the mutual influence between traits should be taken into account, in order to achieve high yield through comprehensive consideration.