Photosynthesis is the basis of plant growth and development. The regulations of photosynthesis by light quality include regulations of stomatal movement, leaf growth, chloroplast structure, photosynthetic pigment, D1 protein and its gene and photosynthetic carbon assimilation by visible light, and effect of ultraviolet light on photosystem II in plant. Blue light and red light can promote the opening of stomata, while the green light can close stomata. Blue light can improve the development of chloroplast, complex light of red, blue and green lights can expand leaf area, and red light can increase the accumulation of photosynthesis production. Effects of different light quality differ in various plants, organs and tissues. Blue light and far red light can promote the accumulation of psbA gene transcription. Most higher plants and green algae have highest photosynthesis rate in orange and red lights, secondly in blue-violet light, and minimum in green light. Ultraviolet light can decline the electron transfer activity of photosystem II. Moreover, questions regarding the effect of light quality on photosynthesis and some topics for future study were also discussed in this paper.