In order to investigate the messenger ribonucleic acid(mRNA) and protein expression status of ANXA1 gene in nasopharyngeal carcinoma cell lines, so as to explore the correlation between ANXA1 methylation status and gene expression, four nasopharyngeal carcinoma (NPC) cell lines, including CNE1, CNE2, 5-8F, 6-10B, and immortalized non-neoplastic human nasopharyngeal epithelial cell line NP69 were cultured in vitro for research. Methylation status of ANXA1 gene was detected by methylation specific polymerase chain reaction (MSP), while mRNA expression level were also evaluated by reverse transcriptional polymerase chain reaction (RT-PCR). Subsequently, different end concentration (0 μmol/L as control, 0.1 μmol/L, 1 μmol/L, 5 μmol/L,10 μmol/L) of 5-aza-2′-deoxycytidine(5-aza-2dC) were added into culture medium of NPC cell lines for 72 hours′ de-methylation treatment, then methylation status of ANXA1 gene were detected by MSP and mRNA expression were evaluated by RT-PCR. In addition, ANXA1 protein expression was detected by Western-blotting. Without de-methylation treatment, ANXA1 gene was methylated in all the four NPC cell lines but NP69, and the methylation extent is correlated with differentiation state and metastasis potential of the cells. mRNA expression was lower in all of the four NPC cell lines without de-methylation treatment compared with NP69, and the expression level was correlated with gene methylation level. 5-aza-2dC de-methylation treatment reversed ANXA1 methylation status, and increased the expression levels of mRNA and protein in all the four NPC cell lines. In summary, the current research verified down-regulated ANXA1 gene expression in NPC cell lines from both mRNA and protein level, the expression down-regulation was mainly caused by gene methylation, and 5-aza-2dC de-methylation treatment restored the down-regulated expression of ANXA1 in NPC cell lines to the level in the non-neoplastic cell line NP69.