Abstract: In order to fully understand and evaluate the excellent characteristics and comprehensive performance of the summer maize （Zea mays L.） varieties that were popularized and applied in the seed market in Xiangyang City, and provide reference for local breeding and promotion of the excellent summer maize varieties, the genetic diversity of 13 agronomic traits of 20 summer maize varieties in the seed market of Xiangyang City was analyzed and the comprehensive evaluation of these summer maize varieties was carried out. The results showed that the coefficient of variation of 13 traits ranged from 3.77% to 58.67%, among which the coefficient of variation of seed rate was the lowest and the coefficient of variation of bald tip was the highest. The genetic diversity coefficient of the traits ranged from 1.59 to 1.97, among which the genetic diversity coefficient of ear size was the lowest, and the genetic diversity coefficient of 100 grain weight was the highest, but on the whole, the genetic diversity coefficient of each trait was relatively low, and the genetic variation richness of varieties was in general level. Accumulated variance contribution of the top 5 factors reached 89.897%, based on this, an adaptive comprehensive evaluation model was constructed to calculate the comprehensive score of the varieties. The summer maize varieties with higher evaluation scores were Xianzhiyuan 66, Dingyou 220 and Woyu No.3, which had better comprehensive performance among the 13 traits measured. The cluster analysis of 20 varieties was divided into 6 groups.

Key words: summer maize（Zea mays L.） varieties, variety, genetic diversity, comprehensive evaluation, Xiangyang City