To investigate the mechanism of asperuloside(ASP) in combating oxidative stress and apoptosis in a rat model of oligoasthenospermia.Methods:A rat model of oligoasthenospermia was established by oral administration of ornidazole.SD rats were randomly divided into a control group，a model group，an ASP group(60 mg/kg)，and pathway inhibitor group(intraperitoneal injection at 2 mg/kg in the 3rd week)+ASP group according to a random number table，with 10 rats in each group.Sperm parameters were assessed.Serum levels of malondialdehyde(MDA)，glutathione(GSH)，superoxide dismutase(SOD)，and glutathione peroxidase(GSH-Px) were measured by enzyme-linked immunosorbent assay(ELISA).Real-time quantitative polymerase chain reaction(qPCR) was used to detect gene expression levels of B-cell lymphoma 2(Bcl-2)，Bcl-2-associated X protein(Bax)，and nuclear factor erythroid 2-related factor 2(Nrf2) in testicular tissue.Western blot was used to measure levels of Kelch-like ECH-associated protein 1(Keap1)，Nrf2，and heme oxygenase-1(HO-1) in testicular tissue.Results:Compared with the control group，the model group showed decreased sperm motility，sperm concentration，GSH-Px，GSH，SOD，Bcl-2，Keap1，Nrf2，and HO-1 levels(P<0.05)，and increased MDA and Bax levels(P<0.05).Compared with the model group，the ASP group demonstrated increased sperm motility，sperm concentration，GSH-Px，GSH，SOD，Bcl-2，Keap1，Nrf2，and HO-1 levels(P<0.05)，and decreased MDA and Bax levels(P<0.05).Conclusion:ASP can effectively improve sperm motility and concentration in oligoasthenospermia rats，reduce apoptosis in testicular cells，and mitigate oxidative stress damage.Activation of the Keap1/Nrf2 signaling pathway may be the underlying mechanism of action.