The purpose of this study was to examine the cardioprotective effects of total flavonoids from Dracocephalum moldavica L. (DML) on ischemia/reperfusion injury (I/R) using an isolated Langendorff rat heart preparation. Hearts were perfused with Krebs-Henseleit (K-H) solution containing DML (100 ug/L) for 10 min before 20-minute global ischemia, then reperfusion was begun with K-H solution for 40 min. The left ventricular developed pressure (LVDP) and maximum up/down rate of left ventricular pressure (±dp/dtmax) were recorded by physiological recorder as the myocardial function. And the level of superoxide dismutase (SOD), malondialdehyde (MDA) and GSH/GSSG ratio were analyzed to determine the oxidative stress status in myocardial tissue. Compared with I/R injury group, pre-incubation with DML (100 ug/L) significantly improved LVDP and ±dp/dtmax during reperfusion. Notably, the level of MDA significantly decreased (P<0.01) in DML group compared to I/R injury group, as well as, the SOD activity (P<0.01) and total glutathione (P<0.05) increased. The results implied that the DML has obviously protective effects on myocardial reperfusion injury.