Abstract: The results of the experiment indicated that the changes of photosynthetic rate showed a single peak curve during the entire process of growth of Gloriosa superba. The yield of tuber and colchicine content could be increased by means of promoting the growth of stem and leaves and elongating the effective photosynthetic time before the peak appeared. The colchicine contentunder the condition of cultivation were higher than that of Gloriosa superba grown under wild condition. It was also found that the light compensation point was at 1.000Lx and light saturation point was from 35,000Lx for favorable range of photosynthesis. The change trend of photosynthetic rate showed a double Peak curve during the day, and a phenomenon of midday depression appeared.