Aim To observe the apoptosis of human leukemic cells induced by F951, a novel bcl-2 antisense oligodeoxynucleotide. Methods HL60 cells were cultured with F951 in variant doses. Apoptotic cells were detected by flow cytometry, DNA ladder, electron microscope observation and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL). Results After HL60 cells were treated for 48 hours, mitochondria apoptotic cells can be detected at the ratio of 3.00% in the untreated group, 13.57% in the FNS control group and 30.95%, 38.08%, 52.55% with 5, 10, 20 ?mol?L-1 F951 respectively; the ratio of cells with caspase activity was 0.08% in the untreated group, 0.14% in the FNS control group and 43.68%, 60.54%, 80.37% with 5, 10, 20 ?mol?L-1 F951 respectively. Typical DNA ladder was seen from gel electrophoresis in F951 treated groups, and more apparent effect in the aspect of inducing DNA ladder had been observed with the improvement of F951 concentration. Detected through TUNEL and electron microscope, apoptotic cells in untreated group and FNS control group can only be found by chance, but very commonly seen in F951 treated groups and more frequently with the improvement of F951 concentration. Conclusion F951 can induce cell apoptosis in HL60 cells. Such effect is achieved through the inhibition of bcl-2 gene expression by F951 which initialize apoptosis passageway in consequence.