Abstract: Objective To enrich the data of tumor cell apoptosis regulated by bcl-2 and antisense bcl-2 by studying the role of antisense bcl-2 gene in mononuclear leukemia cell line U937. Methods A U937 cell model (U937/as-bcl2) was established by transferring the antisense bcl-2 gene into U937 cell.Bcl-2 expression in the model cell was detected by flow cytometric analysis.The model cell growth and survival were analyzed by counting the total and survival cell numbers in normal culture condition and in the presence of recombinant human tumor necrosis factor alpha (rhTNFα). Results ① Bcl-2 expression in the model cell U937/as-bcl2 decreased signicantly,but the model cell had a normal growth and survival in normal culture condition.② The percentage of the survival model cells significantly decreased in the challenge of rhTNFα. Conclusion s ① Antisense bcl-2 gene transfer alone can significantly suppress Bcl-2 expression in U937 cells,but it had no obvious effect on the cell growth and survival in normal culture condition.② Antisense bcl-2 gene transfer can increase the sensitivity of U937 cell to TNFα.