Aim To study the effects of chloride channels on cultured bovine cerebrovascular smooth muscle cells (CSMC) Ca 2+ store operated Ca 2+ influx. Method Cell culture and single intracellular free Ca 2+ concentration was measured in Fura 2/Am flueorescence probed by MetaFluor Fluorescence Ratio Imaging System. Results ① Chloride channel inhibitors 4,4' diisothiocyanostibene 2,2' disulphhonate (DIDS,0.75 μmol/L) decreased Ca 2+ influx significantly induced by endothelin 1 (ET 1),adenosine triphosphate (ATP),cyclopiazonic acid (CPA);Subsequent addition 5 nitro 2 (3 phenylpropylamino) benzoate (NPPB,10 μmol/L) further produced the decrease effect. ② NPPB (10 μmol/L) decreased Ca 2+ influx significantly induced by ET 1,ATP,CPA;Subsequent addition DIDS (0.75 μmol/L) also further produced the effect of decreasing. Conclusion Chloride channel inhibitors DIDS, NPPB inhibited Ca 2+ store operated Ca 2+ influx induced by ET 1, ATP, CPA. DIDS,NPPB sensitive chloride channels participated in the signal transduction of Ca 2+ store operated Ca 2+ influx in cerebrovascular smooth muscle cells.