Objective: To determine the main active extraction of Rubia yunnanensis and verified its anti-myocardial ischemia activity. Method: Norepinephrine (NE) induced contraction activity of rat arterial link with different concentration of extract of R. yunnanensis (1.5×10-3

5×10-3

1.5×10-2

5×10-2

5×10-1 g ·L-1) was compared. The main active extraction was ethyl acetate extraction. Then activity of the ethyl acetate extraction was verified by researches

including mouse hypoxia tolerance under normal pressure

platelet aggregation induced by adenosine disphosphate (ADP) and action on rat myocardial ischemia induced by pituitrin (Pit). Result: The results showed ethyl acetate extraction had significant anti-myocardial ischemia effects that included prolong mouse living time

inhibited ADP induce platelet aggregation

improved myocardial injury induced by Pit

also strengthened the activeness of SOD and reduced MDA content obviously. Conclusion: The ethyl acetate extraction could be the main active extraction of R.yunnanensis for anti-myocardial ischemia.