Abstract: Objective To explore the effect of down-regulation of astrocyte elevated gene-1 (AEG-1) expression on cell proliferation and cell cycle of human pancreatic cancer cell line AsPC-1, and its possible molecular mechanism. Methods The siRNA targeting at AEG-1 gene was transfected into AsPC-1 cells. The protein expression of AEG-1 was detected by Western blot. The AsPC-1 cells were divided into three groups:Untransfection, Lipofectamine and AEG-1 siRNA-transfected group. Cell viability and cell cycle rates were determined via MTT assay and FCM. Results After 48 hours' interference, the gray values of AEG-1 protein was 0.10±0.09, which was lower than in the untransfected group (0.69±0.24) as well as in the liposome transfected group (0.70±0.21, P<0.05). However, there was no difference between untransfected group and liposome transfected group (P>0.05). The AEG-1 expression at the gene level in AEG-1 siRNA-transfected group was reduced by 82% as compared with that in the untranfected group (P<0.05). MTT assay showed that the proliferation of AsPC-1 cells was slower than untransfected group and liposome transfected group. The percentage of cells in G₀/G₁ phase in the AEG-1 SiRNA transfection group was significantly higher and the percentage of cells in S phase was significantly decreased than those in untranfected group and liposome transfected group (all P<0.05). Conclusion The proliferation of human pancreatic cancer cell line AsPC-1 cells were inhibited by AEG-1 siRNA-transfection, changes in the distribution of the cell cycle was involved in the inhibiting effect when there was a lack of AEG-1 expression.