Objective To investigate the in vitro effects of quercitrin on the proliferation and the cytotoxicity of human γδT cells.Methods Peripheral blood mononuclear cells （PBMCs） were isolated from healthy subjects and cultured with isopentenyl pyrophosphate and IL -2 to induce human γδT cells.The hu-manγδT cells were cultured with quercitrin at various concentrations for 48 hours.CCK-8 kits were used to analyze the in vitro proliferation and cytotoxic activities of γδT cells.Flow cytometry was performed to meas-ure the expression of granzyme B and perforin in γδT cells.The expression of p-ERK, p-Akt and Bcl-2 at protein level were detected by Western blot .Results The percentage of human γδT cells in PBMCs was in-creased from （2.96±1.83）%to （88.94±2.36）%after 10 days of culture.The quercitrin at concentrations of 10 to 80 μg/ml could promote the growth of γδT cells and up-regulate the expression of granzyme B , per-forin, p-ERK, p-Akt and Bcl-2 in a dose dependent manner .The cytolytic activities of γδT cells against co-lonic carcinoma cells （ HCT116 ） were enhanced by quercitrin .Conclusion Quercitrin could promote the proliferation of γδT cells and enhance the expression of granzyme B and perforin at certain concentrations in vitro.ERK1/2 and Akt signal transduction systems might be involved in the process .