Objective To investigate the cytotoxic effects of human γδT cells on hepatocellular carcinoma cells in vitro.Methods Normal human PBMC were activated by IPP and rhIL-2.The expansion of γδT cells were analyzed by flow cytometry.The concentration of interferon gamma in the supernatants was detected by ELISA.The cytotoxicity of activated lymphocytes against hepatocellular carcinoma cells were measured by the lactate dehydrogenase release assay in vitro.Results After PBMC activated by IPP and rhIL-2 for 10 days,the proportion of γδT cells were expanded from (4.34±1.79)% to (55.65±6.88 )%.The secretion of interferon gamma expanded significantly after PBMC stimulated by IPP,and reached its peak value at the seventh day.The secretion of interferon gamma is lower if it has no IPP.The activated lymphocytes stimulated by IPP were detected to have cytotoxicity in vitro against human hepatocellular carcinoma ceils.Conclusion The high proportion of γδT cells can be gained in human PBMC activated by IPP,PBMC stimulated by IPP can secret interferon gamma effectively and the activated γδT cells have high cytotoxlcity in vitro against human hepatocellular carcinoma cells.