AIM: To observe the effect of octreotide on apoptosis rate of human pancreatic cancer cells PC-3 after transfected with somatostatin receptor type 2 (SST2) gene.METHODS: SST2 plasmid was transfected into PC-3 cells by liposome. Result of transfection was detected by immunocytochemical staining and West blotting.Apoptosis rates of PC-3 cells under different dosages of octreotide were measured by MTT assay and flow cytometry (FCM).RESULTS: Apoptosis rate caused by octreotide of transfected PC-3 cells was 7.56±1.06% at the dosage of 0.20 μg/mL, 9.25±1.73% at the dosage of 0.40 μg/mL and 14.18±2.71% at the dosage of 0.80 μg/mL. Apoptosis rate caused by octreotide of non-transfected PC-3 cells was 5.76±0.75% at the dosage of 0.20 μg/mL, 6.69±0.80% at the dosage of 0.40 μg/mL and 7.26±1.28% at the dosage of 0.80 μg/mL. Transfected PC-3 cells growth inhibition rate caused by octreotide was 9.36±1.34% at the dosage of 0.20 μg/mL, 12.03±1.44% at the dosage of 0.40 μg/mL and 20.23±4.21% at the dosage of 0.80 μg/mL. Nontransfected PC-3 cells growth inhibition rate caused by octreotide was 6.44±0.66% at the dosage of 0.20 μg/mL,7.65±0.88% at the dosage of 0.40 μg/mL and 9.29±1.32% at the dosage of 0.80 μg/mL. We found that octreotide caused higher apoptosis rate and inhibition rate in transfected groups than in non-transfected groups (P＜0.05)at the tested dosages (0.20, 0.40 and 0.80 μg/mL).CONCLUSION: Deficiency of SST2 was probably the major reason why octreotide had little effect on PC-3 cells.Transfecting SST2 gene could strengthen the ability of octreotide of killing PC-3 cells. It provided an experimental evidence for using both octreotide and transfection with SST2 gene on clinical treatment of pancreatic cancer.