Abstract: Objective: To explore the effect of liposome transfection antisense phosphorothioate oligodeoxynucleotide directed against the coding region of the bcl-2 messenger RNA and the translation site, and G3139 on apoptosis in Raji cells. Methods: Cytotoxic effects were measured by use of MTT method; The expression levels of bcl-2 protein were assayed by immunofluorescence using fluoresce isothiocyanate label. Apoptosis was determined by morphological observation and flow cytometric analysis. Results: The two antisense oligonucleotides and G3139 can reduce bcl-2 protein levels and Raji cells viability (IC₅₀=4.54, 4.72 and 4.26μmol/L, respectively), and induce apoptosis. The scrambled sequence control oligonucleotides and empty liposomes did not alter cell viability、bcl-2 protein expression and apoptosis rates. There was no difference in reducing bcl-2 protein levels and apoptosis rates induced among these three antisense oligonucleotides. Conclusions: The two antisense oligodeoxynu-cleotide of bcl-2 messenger RNA can effectively induce apoptosis of Raji cells. The two antisense sequence and 03139 have similarity antisense effect.