To study the effects of changes in light conditions on the secretion of monoamine neurotransmitters in the hypothalamus of rats by using the special natural conditions of total solar eclipse according to the “yin-yang of the four seasons and the five viscera” theory. Methods:Rat hypothalamus was taken before, during, and after solar eclipse. The content of monoamine neurotransmitters in rat hypothalamus was determined by HPLC. Results:Compared with the pre-eclipse group and the eclipse group, the content of 5-HIAA in the hypothalamus decreased significantly (P<0.01), and 5-HT decreased significantly (P<0.01). Conclusion:Monoamine neurotransmitters are sensitive to changes in the light environment. Under light sudden changes, the monoamine neurotransmitter content of the hypothalamus has a significant change.