Abstract:In order to investigate the effects of different stress on biological and chracteristics of seedlings from maize, different concentrations of brassinolide was applied to maize seed.The effects of EBR on relative electric conductivity (REC),malondiadehyde (MDA) content,superoxide dismutase (SOD) activity,peroxidase (POD) activity,catalase (CAT) activity, ascorbate peroxidase (APX) activity, praline,soluble sugar contents and different growth indicators were studied under NaCl and low temperature stress(15℃).The results indicated that 0.050 mg·L-1 EBR significantly alleviated the damage caused by 180 mmol·L-1 NaCl. Specifically, seed germination rate, germination potential, germination index, vigor index and relative water content, root/shoot ratio were increased significantly, the relative electric conductivity decreased, reducing the salt harm index; plant height, root length and plant fresh weight was also increased significantly;the activities of POD,CAT,SOD and APX were increased correspondingly, and contents of proline and soluble sugar increased correspondingly, while contents of MDA were decreased.Under low temperature (15℃) stress, compared with the normal temperature(25℃), the concentration range of 0.001~1.000 mg·L-1 EBR can increase the maize plant height, root length, fresh, dry weight per plant and germination rate,0.100 mg·L-1 EBR effect was the best.It also can increase the germination potential, but no obvious regularity. Results suggested that EBR can relieve salt and low temperature stress of maize,its mechanism may be appropriate concentration of EBR can activate the ability of enzyme scavenging free radical, the reaction between enzyme could alleviate the damage by stress. The study provide theoretical foundation for the research of maize stress resistance.