Abstract: 【Objective】To investigate the effect of mogroside V(MV)on alleviating fat accumulation in mice under continuous illumination,and to provide reference for the application of Siraitia grosvenori in healthy breeding of livestock and poultry.【Method】15-week-old male C57BL/6 mice were randomly divided into control group(light:darkness=12 h∶12 h),continuous illumination group(24 h continuous light exposure),and continuous illumination with MV treatment group100 mg/(kg·d). During the five weeks treatment,the body weight and food intake of the mice were monitored.And the body fat content and energy metabolism of the mice were detected. After the treatment,the mice were sacrificed,and iWAT and eWAT of the mice were weighed and stained with hematoxylin-eosin(H-E)to observe the morphology of the adipose tissue. Besides,the expression level of lipometabolism and metabolizing-related genes in the adipose tissues was detected by real-time quantitative PCR.【Result】During the five weeks treatment,there were no significant differences in the body weight and food intake among three groups mice(P>0.05). But continuous illumination could extremely significantly increase the body fat content(P<0.01,the same blow). The basic metabolic parameters such as oxygen consumption,carbon dioxide emission and heat production were extremely significantly decreased,while the percentage of iWAT and eWAT and cell diameter were extremely significantly increased. In iWAT and eWAT of continuous illumination group,the relative expression levels of fat synthesis related genes(Fabp4、Pparg2 and Zfp423)and inflammatory response related genes Nfkb1 were extremely significantly up-regulated,and the relative expression levels of lipolysis related genes Lpl were extremely significantly down-regulated,and energy metabolism genes(Sirt1 and Ppargc1a)were significantly(P<0.05)or extremely significantly down-regulated. However,MV treatment could restore the above indexes changes to the level of control group. These results indicated that MV could effectively improve the energy metabolism disorder,fat accumulation,and the abnormal expression of fat metabolism,energy metabolism and inflammatory response related genes caused by continuous light exposure.【Conclusion】Continuous light exposure can induce the body fat accumulation without changing the energy intake,affecting the body metabolism and health. MV can effectively alleviate metabolic disorders by regulating the expression of metabolism-related genes Sirt1and Ppargc1a. Besides,MV can effectively alleviate fat accumulation induced by continuous light exposure in mice through promoting lipolysis and inhibiting the expression of adipose synthesis-related genes.