OBJECTIVE To study the regulatory mechanism of ethanol extract of Turkish Galls on proliferation and migration of colorectal cancer cells HCT- 116 and Caco- 2 based on janus kinase 2（JAK2）/signal transducer and activator of transcription 3 （STAT3）signaling pathway. METHODS CCK-8 method was used to detect the effects of 0.05，0.1，0.2，0.3，0.4 and 0.5 mg/mL ethanol extract of Turkish Galls on the proliferation of HCT- 116 and Caco- 2 cells after treated for 12，24，48 and 72 h. After treated with 0.1，0.3，0.5 mg/mL ethanol extract of Turkish Galls for 24 h，the migrations of HCT- 116 and Caco- 2 cells were detected by scratch test ；the level of reactive oxygen species （ROS）was detected by fluorescent probe method. The levels of interleukin-6（IL-6）and tumor necrosis factor-α（TNF-α）in cell supernatant were detected by ELISA . The phosphorylations of JAK2 and STAT 3 as well as the expressions of B-cell lymphoma- 2（Bcl-2）and Bcl- 2 associated protein X （Bax）were detected by Western blot assay. RESULTS Compared with blank control ，0.05，0.1，0.2，0.3，0.4 and 0.5 mg/mL ethanol extract of Turkish Galls could significantly inhibit cell proliferation after treated for 12，24，48，72 h（P＜0.05）. After treated with 0.1，0.3 and 0.5 mg/mL ethanol extract of Turkish Galls for 24 h，the scratch healing rate of 2 kinds of cells ，the levels of IL- 6 and TNF-α in the cell supernatant ，the phosphorylation of JAK 2 and STAT 3 as well as the expression of Bcl- 2 protein were all significantly decreased （P＜0.05）；the level of ROS and protein expression of Bax were increased significantly （P＜0.05）. CONCLUSIONS The ethanol extract of Turkish Galls can inhibit the proliferation and migration of HCT- 116 and Caco- 2 cells. The mechanism may be related with down-regulation of protein expression of Bcl- 2 and up-regulation of protein expression of Bax by increasing the accumulation of intracellular ROS ，down-regulating the expressions of inflammatory factors IL- 6 and TNF-α and the phosphorylation of JAK2 and STAT 3 in JAK 2/STAT3 signaling pathway.