AIM To investigate whether protein tyrosine phosphorylation and Cl - channels be involved in transient receptor potential(TRP) protein mediated store operated calcium influx(SOC) in HEK293 cells. METHODS Human TRP1(hTRP1) and human TRP3(hTRP3) cDNA were transfected to HEK293 cells respectively using lipofectAMINE reagent, the effects of genistein, furosemide and 4,4 diisothiocyanostilbene 2,2 disulphonic acid(DIDS) on thapsigargin(TG) induced Ca 2+ influx were determined by Fura 2/AM spectrophoto fluorometry. RESULTS Compared with untransfected cells, the significant enhancement in TG induced Ca 2+ influx in hTRP1 transfected HEK293 cells was found, but not in hTRP3 transfected ones. Genistein 5-30 μmol·L -1 , furosemide 1-8 μmol·L -1 and DIDS 0.5-1.0 μmol·L -1 inhibited TG induced Ca 2+ influx in hTRP1 transfected cells. CONCLUSION hTRP1 Protein may be one of components of TG induced SOC in transfected HEK293 cells. Tyrosine phosphorylation and Cl - channels may be involved in TG induced Ca 2+ influx and tyrosine kinase may regulate hTRP1 protein directly.