We isolated rosmarinic acid from stem barks of Euonymusalatusmethanol extracts. Rosmarinic acid showed a strong inhibitory effect of MMP-9 activity in a concentration-dependent manner without cytotoxic effect at dose of 50mg/ml. Rosmarinic acid significantly decreased total number of Hep3B cells invaded in matrigel precoated transwell chambers. So, we suggest that stem barks of E.alatus could be suitable for cancer treatment and chemopreventive drugs.