Abstract: Objective：To investigate the role of As₂S₂ on C13K/DDP cells proliferation and apoptosis in vitro. Methods：C13K/DDP cells were incubated with different concentration of As₂S₂ (4, 6, 8, 10μmol/L) at various periods(24, 48, 72h).The cell growth was measured by MTT. Apoptosis was detected by double staining flow cytometry (FCM). The expression of BCL-2,BAX and AKT was examined by Western blot analysis. Results：Compared with DDP group, the proliferation of C13K/DDP cells treated with As₂S₂ was significantly inhibited in dose- and time-dependent manner (P<0.01). FCM analysis showed that As₂S₂ could markedly induce C13K/DDP cells apoptosis. The apoptotic rates of C13K/DDP cells treated with As2S2 (6,8μmol/L) after 24h and 48h were (16.05 ±2)%, (22.30 ±3)% and ( 28.94±1.8)%, (37.85 ±3)%respectively， there was significant difference compared to control group ［(7.82±1.2)%,(9.80± 2.6)%］ and DDP group［(9.45±2)%,（14.74±3.2）% )(P<0.05). BCL-2 and AKT expression was down-regulated by As₂S₂ and BAX expression was up-regulated by As₂S₂. Conclusion ：As₂S₂ could inhibit the proliferation of C13K/DDP cell and induce cell apoptosis，which may be related to the BCL-2 or AKT down-regulation and BAX up-regulation.