Abstract: Objective 　To study the effect s of blocking chloride channel on the proliferation and RNA2de2 pendent adenosine deaminase1 (ADAR1) for human larynx cancer Hep22 cell lines. Methods 　Hep22 cell was used as a target . The effect s of chloride channel blocker (NPPB) on the proliferation of Hep22 cell were evaluated by means of MTT assay. Semi2quantitative reverse t ranscription polymerase chain reac2 tion (RT2PCR) was performed to measure the expression of ADAR1 mRNA in selected Hep22 cell clones. Results 　Cont rolling the proliferation of Hep22 depended on the consistency of chloride channel blocker (NPPB) . The relative intensities of ADAR1 mRNA of Hep22 was remarkably different before and af ter it s chloride channel was blocked. Conclusion 　Our result s suggest that blocking the chloride channel could rest rain the proliferation of Hep22. Normal expression and functioning of chloride channel is essential for the maintenance of proper cell growth. There is close correlation between the chloride channel and A2 DAR1 mRNA of Hep22.