Abstract: The research was carried out to study the effects of four kinds of chemical reagents (KNO3, GA3,KMnO4 and NaOH) on seed germination and seedling growth characteristics of Senna alata L. The results indicated that all concentrations of KMnO4 and GA3 promoted the germination and seeding growth of S. alata L., and 0.1g/LGA3 and 4g/L KMnO4 were the most effective reagents. All KNO3 concentrations promoted the germination, but the growthMof seedlings were not affected. The germination process and shoot height were depressed under different concentrations of NaOH, the larger the concentration was, the more severely the seed germination and seedling