Abstract: Objective To study the anti-tumor effect of Indirubin-3'-monoxime combined with Nedaplatin(Nap) on the human esophageal cancer cell line EC-1，and to reveal its methanism. Methods Human esophageal cancer line EC-1 was treated in vitroby Indirubin-3'-monoxime with or without Nap in various concertration. The cell growth was evaluated by MTT assay，cell cycle distribution were observed by flow cytometry，and the expression of apoptosis-related genes were analyzed by immunohistochemical staining method. Results Compared with Indirubin-3-'monoxime or Nap individual drug groups，Indirubin-3'-monoxime combined with Nap obviously increased the inhibitory rate of the human esophageal cancer cell line EC-1.In the groups treated by the combinatio of Indirubin-3'-monoxime and Nap, the cell cycle distribution was altered.In this case, the ratio of G₀/G₁ phase cell decreased，the G₂/M phase cell increased, the expression of following the treatment with Indirubin-3'-monoxime combined with Na，with Bcl-2 gene down-regulated，and the expression of Bax gene expression up-regulated. Conclusion Indirubin-3'-monoxime combined with Nap may obviously increase the inhibitory rate of the human esophageal cancer cell，and its mechanism may be to regulate cell cycle and to increase apoptosis-inducing effect which is regulated by several genes.