Aim Anti-apoptotic factor Humanin may have a protective effect on endothelial function and progression of atherosclerosis by modulating oxidative stress and apoptosis in the developing plaque. But there has been no report on whether it has an impact on platelet hypersensitivity in the atherosclerotic mouse models. Here we examined the effect of Humanin analogue （［Gly14］-Huamnin,HNG） on the development of atherosclerosis and platelet hypersensitivity in low-density lipoprotein receptor knock-out mice. Methods Mice （8 weeks old） were grouped into wild type mice on normal chow diet （CD） and LDLR^-/- mice on high fat diet （HFD） with or without HNG injection. At week 4,12,24,blood was obtained from the inferior vena cava and platelets were isolated and measured for aggregation in a Chrono-log lumi-aggregometer and serum lipid level was measured. At the right time,the aorta was stained with Sudan IV and lipid deposition was quantified using Image-Pro Plus. Results After 24 weeks on HFD,LDLR^-/- mice showed large area of plaques formed in the aorta and an altered lipid profile as compared to WT mice on CD. Platelets of LDLR^-/- mice on HFD showed significantly higher reactivity than WT mice on CD in response to ADP （n10,P<0.01）. Most importantly,administration of HNG inhibited the formation of atherosclerotic plaque in the aorta （n10,P<0.01） and decreased platelet reactivity to ADP （n10,P<0.01） in LDLR^-/- mice on HFD. Conclusion Our data showed that HNG reduces platelet hypersensitivity in the setting of hyperlipidemia,providing a potential alternative mechanism by which HNG reduces plaque formation.