Abstract: Tubers of Pinellia ternata were used as materials, the effects of different concentrations of brassinolide（BR） on yield and quality of Pinellia ternata by pot experiment were studied, in order to provide a reference basis for improvement of yield and quality of Pinellia ternata.The results showed that the low concentration of BR(0.01,0.10 mg·L^-1 and 0.20 mg·L^-1) significantly increased the contents of alkaloid, β-sitosterol, free amino acid, soluble sugar, soluble protein and vitamin C,and phenylalanine ammonia-lyase activity.The high concentration of BR(1.20 mg·L^-1) markedly reduced the contents of flavone, alkaloid, β-sitosterol, free amino acid, total soluble sugar, soluble protein and vitamin C content, and phenylalanine ammonia-lyase activity.When the concentration of BR were 0.05,0.10,0.20 mg·L^-1 and 1.20 mg·L^-1,the bulbil yield was significantly increased, thus the yield of Pinellia ternata was increased.Comprehensive analysis showed that low concentration of BR(0.10-0.20 mg·L^-1) not only improved the quality, but also increased the yield of Pinellia ternata in the experimental condition.