Aim To investigate the inhibitory effect of Evodiamine on JAK2/STAT3 signal pathway in human colorectal cancer cell line HCT-116 . Methods Cells were cultured with 6. 0 μmol·L-1 Evodiamine for 2, 4 and 6 h, respectively. Cell nuclear morphology was detected by Hoechst staining and protein expression levels of JAK2 , p-JAK2 , STAT3 and p-STAT3 were examined by Western blot. Cells were treated with dif-ferent concentrations of AG490 for 48 h to select proper working concentration and cells treated with 6 μmol · L-1 EVO and 50 μmol · L-1 AG490 to compare the modulatory effect of EVO with AG490 on JAK2/STAT3 signal pathway. Results Hoechst staining revealed that Evodiamine could induce cells apoptosis, chroma-tin condensation gathered and typical apoptotic mor-phological changes in a time-dependent manner;West-ern Blot suggested that EVO could inhibit p-STAT3 significantly. After treatment with AG490, JAK2/STAT3 signal pathway was inactivated, the inhibitory effect of EVO on p-STAT3 was stronger than that of AG490 , while EVO combined with AG490 could fur-ther inhibit the expression of p-STAT3 significantly. Conclusions The anticancer effect of Evodiamine is mainly mediated by the modulation of JAK2/STAT3 signal pathway in HCT-116 cells.