Taking Xinjiang wild onion and common welsh onion （Zhangqiu welsh onion and Japanese Yuanzang welsh onion）as test material，this paper studied the effects of drought stress on physiological indexes of 3 kind onions by potted water control method．The results showed that the overall growth of wild onion was weak，but with the decrease of the relative water content in soil，the changing range of morphological indicators，including plant height and leaf length of wild onion was small．The contents of soluble sugar, soluble protein，and proline in leaves and pseudostems of wild onion，root activity and antioxidant enzyme activity were all higher than those of common welsh onion．While，the increasing range of relative conductivity，MDA，H₂O₂ content were less than that of common welsh onion．And the increase range of soluble sugar，proline content，SOD，POD activity were greater than that of common welsh onion．The decreasing range of root activity was smaller than that of the common welsh onion．Based on various indicators，the drought resistance of wild onion is superior to that of Zhangqiu and Japanese Yuanzang welsh onion．