OBJECTIVE： To observe the protective effect of different extraction samples from Salvia miltiorrhiza decoction on acute myocardial ischemia model mice. METHODS： 96 mice were randomized into blank control group （normal saline）， model group （normal saline）， positive drug group [Compound Salvia miltiorrhiza tablet， 4.6 mg （crude drug）/（kg·d）]， high-dose， medium-dose and low-dose groups of water extract， supercritical CO2 extract and supercritical CO2 extract+dregs water extract [24， 12， 6 mg （crude drug）/（kg·d）]， with 8 mice in each group， 12 groups in total. They were given medicine intragastrically once a day. On sixth day， 30 min after giving drugs， those groups were given isoprenaline 20 mg/kg， ih， to induce myocardial ischemia model except for blank control group， once a day， for consecutive 3 d. Electrocardiogram ST segment variation of mice were observed. The times and duration of buccal respiration were observed after rapid decapitation， and the activities of CK and LDH in serum were determined. RESULTS： Compared with blank control group， electrocardiogram ST segment and the activity of CK and LDH increased in model group， while the times and duration of buccal respiration after rapid decapitation reduced （P＜0.01）； compared with model group， above indicators of medication groups had been improved （P＜0.01）， and were positively correlated to drug concentration； the indicators of supercritical CO2 extract+dregs water extract group were most close to those of blank control group. CONCLUSIONS： Different extraction samples from Saliva miltiorrhiza decoction all have protective effect on acute myocardial ischemia model mice， and the protective effect of supercritical CO2 extracting+dregs water extracting sample of Salvia Miltiorrhiza decoction is best.