Abstract: Objective To research the effect of nitric oxide in the process of cadmium-induced acute liver injury and intervention with Sagittaria Sagittifolia.Methods Thirty male Sprague-Dawley rats were randomly assigned into six groups,each of six.The rats were pretreated intragastrically with 25%,50%,75% Sagittaria Sagittfolia extract(2ml/100g)or distilled water once daily for ten days.Twenty-four hours after the last dosing,animals were administered with CdCl₂(20μmol/L/kg)intraperitoneally,control animals were given distilled water only.Twenty-four hours after the intoxication,the serum LDH,GPT activity and NO concentration,liver MDA content and nitric oxide synthase(NOS)activity were measured in each group above.Results Compared to the control,cadmium could increase the serum LDH,GPT activity and liver MDA content(P<0.05);Treatment of rats with 50% and 75% Sagittaria Sagittifolia extract could decrease the serum LDH,GPT activity and liver MDA content(P<0.05);Sagittaria Sagittifolia extract inhabited liver NOS activity and decrease serum NO concentration in dose-dependent manner(r=-0.959 6,-0.995 6,P<0.05)also.Conclusion It is suggested that NO seems to be involved in cadmium-induced acute peroxidative liver injury on rats and the intervention effect of Sagittaria Sagittifolia on rats.