Abstract: The effects of different light qualities(blue, red, UV-A, UV-B)on the quality of cucumber fruit growing in solar greenhouse were investigated and the contents of vitamin C, protein, and deoxidized sugar were measured. The results show that the vitamin C content of cucumber fruit under UV-B and red light is higher than that under UV-A and blue light; the contents of protein and deoxidized sugar in fruit under blue light are the highest among these under all the treatments. Under UV-A light the yield is higher than that under any other treatments.