This study was carried out both laboratory and field experiment to research the effects of three different light intensity on capsaicin content of hot pepper fruits during the growing stage, the varieties in the study were in different hot levels named No.4 Xiangyan (mid-hot) and No.3 Jingjianjiao (very hot). The study showed that capsaicin content increased accompanied with light intensity weakening. There was an inverse relationship between capsaicin content and peroxidase activity.