Abstract: With pepper as the material， the effect of five light qualities （R， B， 7R/1B， 5R/1B and CK） on the seed germination， seedling growth and cold resistance of pepper were evaluated according to subordinate function values analysis. The results showed that the red light had a remarkable impact on the seed germination of pepper， and its germination rate was about 1867% higher than that of the control group. Meanwhile， with the increasing ratio of red light in the compound light of blue and red， the germination rate， germination index and vigor index increased gradually. The pepper seedling height in red light treatment was the highest， about 801% higher than that of the control group. The stem diameter was greatest in blue light treatment， which was 224% higher compared with the control group. The root length of seedling was the longest in the treatment of 7R/1B， which was 96.4% higher than that of the control group. There was significant difference in fresh weight and dry weight of seedlings under different light qualities， for instance， the fresh weight under red light was the largest， which increased by 33.3% compared with the control group; and the dry weight was the largest in the treatment of 7R/1B， which was 87.5% higher than the control group. The chlorophyll fluorescence parameters including Fv/Fm， NPQ and ФPSII were the highest in the treatment of 5R/1B， but the lowest under blue light. According to the comprehensive evaluation of seed germination index， seedling growth index and chlorophyll fluorescence parameters， 5R/1B was the best （55.97%）， and the control group was the lowest （49.05%）. When evaluation was conducted with the relative chlorophyll content， electrolyte permeability， SOD， POD， and CAT activities measured under low temperature treatment， 5R/1B （58.16%） showed the best effect and the blue light was the poorest （43.60%）. Thus， it can be concluded that the optimal light quality for the seed germination and seedling growth of pepper was 5R/1B.

Key words: light quality, pepper, cold resistance