Abstract: In order to study the performance of root traits of cotton（Gossypium spp.）seedlings under drought stress, 17 cotton lines with different drought tolerance were bred by Handan Academy of Agricultural Sciences. The root characteristics of different cotton resources were compared by PEG6000 drought stress. The root image scanning and WinRHIZO software were used to analyze the root system. The relative growth rate of root length, relative growth rate of root surface area and relative growth rate of root average diameter of different varieties were compared. The drought resistance of the tested varieties was determined by variance analysis, multiple comparison and systematic clustering. The results showed that there were some differences in drought resistance of different cotton varieties under 15.0% PEG6000 stress. According to cluster analysis and drought resistance performance, cotton varieties could be divided into 3 categories： the first category was HL64; the second category included HL28, HL59, HL66, HL60;the third category was HL31,HL47,HL68,HL27,HL45,HL33,HL44,HL29,HL69,HL34,HL43, and HL42.

Key words: cotton（Gossypium spp.）, drought resistance at seedling stage, PEG, root characteristics