Taking pepper（Capsicum frutescens L.）‘Xiangyan No.5’ as material， this experiment applied water controlled pot cultivation under 2 different drought stresses（ mild， and moderate） conditions， and studied the effect of drought stress on pepper contents of capsaicin， dihydrocapsaicin and vitamin C， and the changes in leaf blade photosynthetic characters. The result showed that the contents of capsaicin and dihydrocapsaicin were increased 63.36% and 63.03%， respectively than the control under mild drought stress 60 days after flowering. It also showed that 40 days and 50 days after flowering， different degrees of drought stress could remarkably improve the contents of vitamin C in pepper. Sixty days after flowering， mild drought treatment could push the vitamin C content to the highest level， while the moderate drought stress could make the vitamin C content lower than that of the contrast. After the treatment of different degree drought stress， the net photosynthetic rate of pepper plant shew the tendency of firstly increase then decline， and gradually decreased along with the enhancement of drought degree.