OBJECTIVE To in vestigate inhibitory effect s of gallic acid （GA）on human esophageal cancer TE- 1 cells in vitro and its potential mechanism. METHODS The effects of GA on the proliferation of TE- 1 cells were determined by MTT assay after treated with GA for 24 h and 48 h. Cell fluorescence counting （CCK-F）method and inverted fluorescence microscope were used to observe the changes in the number and morphology of TE- 1 cells after treated with GA. The change of cell migration ability was detected by scratch test. The effects of GA on the colony-forming ability of TE- 1 cells were tested by plate colony formation experiment. Cell apoptosis was detected by flow cytometry. Fluorescence probe （DCFH-DA）method was used to observe reactive oxygen species （ROS）production. Western blot assay was used to detect the expression of caspase- 3，caspase-9，Bcl-2，Bcl-2 associated X protein （Bax），cyclin D 1 and cyclin D 3. RESULTS GA significantly reduced the proliferation ability of TE- 1 cells in time and concentration dependent manner. the IC 50 of GA to TE- 1 cells were （281.22±26.81）μmol/L（24 h）and（220.90±31.15） μ mol/L（48 h），respectively. Compared with control group ，the cells in the administration group showed shrinkage ，sparse arrangement and nuclear pyknosis ，and the number of cells decreased significantly. Compared with control group ，the cell migration ability and colony formation ability were decreased significantly in administration groups （P＜0.01 or P＜0.05）. The apoptosis rates of TE- 1 cells were （6.21±0.32）％，（12.59±0.58）％ and（15.41±0.41）％ after treated with 100，300 and 500 μmol/L GA for 24 h，all of which were significantly higher than （5.29±0.28）％ of control group （P＜0.01 or P＜0.05）. Except for GA 100 μmol/L group，the level of ROS in other administration groups were significantly increased （P＜0.01 or P＜0.05）. Compared with control group，the expressions of Bcl- 2（only GA 200 μmol/L group），Bax（except for GA 100 μmol/L），caspase-3 and caspase- 9（except for GA 100 μmol/L）were increased significantly （P＜0.01 or P＜0.05），while the protein expressions of Bcl- 2（except GA 100， 200 μmol/L group），cyclin D 1 and cyclin D 3 were significantly decreased （P＜0.01 or P＜0.05）. CONCLUSIONS GA can inhibit the proliferation of esophageal cancer TE- 1 cells， E-mail：1209364115@qq.com restrict their migration ability and colony-forming ability ，and promote apoptosis. The mechanism may be related to the increase of ROS level ，up-regulation of the expressions of pro-apoptotic proteins caspase- 3，caspase-9 and Bax ，and down-regulation of the expressions of anti-apoptotic protein Bcl- 2，cyclin D1 and cyclin D 3.