Abstract: Objective: To explore the effect of Sini decoction(SND) on the activity of lactate dehydrogenase(LDH) and the concentration of malondialdehyde(MDA) after cardiopulmonary resuscitation(CPR) in rats.Methods: Adult Wistar rats were randomly divided into 3 groups,the normal control group,the CPR group and the SND treatment group.Model of CPR was produced by injecting 2% KCl quickly through external jugular vein.Then the rats,heartbeat and respiration stoped at once,after 6 minutes were carried out CPR.For being observed for 60 minutes,adult Wistar rats were sacrificed.The activity of LDH and the concentration of MDA in cerebral cortex were determined.0.9%saline was fed at the dosage of 0.1 ml/100 g for three days preoperatively in the normal control group.SND was fed at the dosage of 0.1 ml/100 g for three days preoperatively in the SND group.Results: The activity of LDH in cerebral cortex was significantly higher in the SND group than in CPR group(P<0.01),while the concentration of MDA was markedly lower than those in CPR group(P<0.01).The activity of LDH in cerebral cortex were lower in the SND group than in the normal control group(P<0.05),while the concentration of MDA was higher than those in the normal control group(P<0.01 and P<0.05).Conclusions: The results suggest that Sini decoction possiblely play a membrane protective role by suppressing Lipid Peroxidation(LPO) in cerebral cortex and maintaining cells membrane stability after CPR.