In order to clarify the adaptable difference of different drought resistance cotton varieties under drought stress,we took ‘Xinluzao 50’(drought-tolerant) and ‘Xinluzao 27’(drought sensitive) as the material in this test.The active oxygen species generation,electrolyte leakage,antioxidant enzyme activity change,and the expression profiles of some antioxidant enzymes genes,osmotic regulation genes,transcription factors were analyzed under drought stress.The results showed that:(1)the conductivity and MDA content in cotton leaves increased gradually with drought stress strengthen,and recovery after rehydration;the antioxidant enzyme activities of drought-tolerant variety ‘Xinluzao 50’ significantly higher than that of drought sensitive variety ‘Xinluzao 27’ after drought stress 6 and 8 days.(2)Gene expression profiling under drought and rewater treatment showed that cotton superoxide dismutase (GhSOD) only expressed under drought stress and had no difference between two varieties,GhBADH,GhNCED,GhP5Cs and transcription factors GhPHD1,GhPHD5,GhPHD6,GhPHD10 in drought-tolerant variety ‘Xinluzao 50’ had higher expression level than that in drought sensitive variety ‘Xinluzao 27’.The results demonstrated that drought-tolerant variety had lower active oxygen content,conductivity and MDA content,higher antioxidant enzymes activity,and the expression of drought relate genes had higher level compared with drought sensitive variety under drought stress.