Objective：The current study aims to assess the efficacy of total saponins of Panax notoginseng（PNS）supplementation on platelet hyperreactivity in hyperlipidemic mice as well as to clarify the underlying mechanisms in vivo. Methods：Healthy male C57BL/6J mice（aged 8 weeks）were randomly divided into four groups and fed either a low-fat diet（LFD group），a LFD supplemented with PNS（200 mg/kg diet，LFD+PNS group），a high-fat diet（HFD group），or a HFD supplemented with PNS（200 mg/kg diet，HFD+ PNS group）for 12 weeks. After that all mice were killed，and the plasma and purified platelets were prepared，followed by measurement levels of plasma lipid profile using commercial assay kits. A platelet aggregometer was used to measure maximal aggregation ratio. Platelet activation was determined by flow cytometry and enzyme - linked immunosorbent assays. Real - time PCR technique was used to detect CD36 mRNA expression，and Western blot was used to measure protein expression levels of CD36 and phosphorylation of Src and p47phox. Results：When compared with those in LFD group，the plasma levels of total cholesterol，triglyceride and low density lipoprotein cholesterol were significantly increased in HFD group，which were greatly decreased by PNS supplementation. Moreover，PNS supplementation favorably attenuated HFD-induced platelet aggregation and activation in response to an agonist thrombin，including inhibiting platelet surface CD62P expression，and platelet factor 4（PF4）and chemokine ligand 5 （CCL5）release，indicating a potent inhibitory effect of PNS on HFD-induced platelet hyperreactivity. Mechanistically，CD36 mRNA and protein expression increased by HFD were significantly down-regulated by PNS supplementation. Moreover，PNS supplementation also greatly attenuated HFD-induced activation of downstream signalling pathways mediated by CD36，including down-regulating Src and p47phox phosphorylation. Furthermore，it is found that platelet surface CD62P expression isolated from LFD mice in response to adenosine diphosphate were increased by adding hyperlipidemic plasma from HFD mice，which was greatly decreased in LFD+PNS group. This significant difference was abolished when pretreated with an anti-CD36 monoclonal antibody FA6-152. Conclusions：PNS supplementation attenuates platelet hyperreactivity in mice fed a high - fat diet possibly through down - regulating CD36 signalling pathway. The current study may provide potential value for PNS to improve thrombosis in hyperlipemia and the related chronic metabolic diseases.