Abstract： Objective To explore the effect of DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-Aza-CdR) on proliferation and tumor suppressor gene PRDM1α expression in Burkitt's lymphoma cell line NAMALWA. Methods MTT was used to study the impact of DNA methylation inhibitor on proliferation in NAMALWA cells,and comparative real-time reverse transcription-polymerase chain reaction (RQ-PCR) with SYBR Green assay was used to detect PRDM1α gene expression. Results MTT results showed that 5-AzaCdR inhibited proliferation of NAMALWA cells in a dose-dependent manner.After treated with 5-Aza-CdR for 72 h at 0.01,0.0625,0.1,0.125,0.25,0.5,1,2 and 4 μmol/L,the inhibition rates were 21.93 ％,39.23 ％,47.69 ％,50.37 ％,53.54 ％,57.72 ％,62.31％,65.68 ％,67.87 ％,respectively,and the differences of absorbance among the groups were also statistically significant (all P＜ 0.01). Meanwhile, 5-Aza-CdR could induce the re-expression of PRDM1α, and △Ct of 0.5, 1, 2 μmol/L groups showed significant differences compared with control group (all P ＜ 0.05). Conclusion DNA methylation inhibitor 5-Aza-CdR can significantly inhibit the proliferation of Burkitt' s lymphoma cell line NAM ALWA,and the possible mechanism of this inhibition may be induction of demethylation and re-expression of PRDM 1α.