Abstract: The drought resistance from regenerative plants of hairy root cultures in maize was investigated in this paper. The grey system analysis was used in this study for analyzing the change of the morphological characteristics, which included plant height stress index(PHSI), dry matter stress index(DMSI), number, length, volume, dry weight, total absorbing area, active absorbing area, and root/shoot ratio. The results revealed the close relationships among dry weight, DMSI, leaf area of single plant, root/shoot ratio, volume and drought resistant index. Because of high lines of the regenerative plants from hairy root cultures in maize, it has close relationship with drought resistance and keeps strong hydraulic root signal under water stress.