Objectives : In this study, we investigate that Ulmi cortex extract contributes to growth inhibitory effect and anti-cancer activity on the HT-29 human colon cancer cells. Methods : Ulmi cortex was extracted from the leaves of the plant using water. The Ulmi cortex extract was treated to different concentrations for 24 hr. Growth inhibitory effect was analyzed by measuring FACS study and MTT assay. Cell cycle inhibition was confirmed by kinases assay. Cell apoptosis was confirmed by surveying caspases cascades activation using Western blot. Results : Exposure to Ulmi cortex extract (0.4mg/ml) results in an inhibitory effect on cell growth in HT-29 cells. Growth inhibition by Ulmi cortex extract in HT-29 cells was related with the inhibition of proliferation and induction of apoptosis. The Ulmi cortex extract induces G1-cell cycle arrest and DNA fragmentation in HT-29 cells. Furthermore, Ulmi cortex extract induces cell apoptosis through the activation of caspases-3 and PARP cleavage. Conclusion : Ulmi cortex extract induces apoptosis in human colon cancer cells, therefore, we suggest that Ulmi cortex extract can be used as a novel class of anti-cancer drugs.