Abstract: Objective To explore the effects of red and blue monochromatic LED light sources on the learning and memory ability of mice.Methods Fifty mice were divided into blank control group,red light irradiation for 5 min group,red light irradiation for 10 min group,blue light irradiation for 5 min group,Blue light irradiation for 10 min group,10 mice in each group.The control group was not irradiated,and the other four groups were irradiated 2 times per day.After 9 weeks,jump table test was used to evaluate the learning and memory ability of mice.Nitric oxide (NO),nitric oxide synthase (NOS) and acetylcholinesterase (AchE) changes were observed in brain tissue of mice.Results In the test for mistakes within 5 min,the blank control group was the highest,and there were significant differences between the blank control group and the other four groups (P ＜0.01).In the test for mistakes within 3 min,the blank control group was the highest,and there were significant differences between the blank control group and the other four groups (P ＜ 0.01).In the blank control group,the NO and NOS levels were significantly lower than those in the red light group and blue light group,and the AchE was significantly higher than the red light group and blue light group (P ＜ 0.01).Conclusion Both blue and red light can improve the learning and memory ability of mice,but red light irradiation for 5 minutes is more effective in improving the learning ability of mice.