LRRC4, leucine-rich repeat C4 protein, is a new member of leucine-rich repeat (LRR) superfamily. It is a novel tumor suppressor. LRRC4 inactivation is commonly found in glioma cell lines and primary glioma biopsies. Previous study did not find any genetic alteration of LRRC4 in primary glioma. In order to explore an alternative mechanism underlying inactivation of LRRC4 in glioma, glioma cell lines SF126 and SF767 were treated by methylase inhibitor 5-Aza-2′-deoxycytidine (5-Aza-CdR). Methylation-specific PCR was used to examine the methylation status changes of LRRC4 promoter in SF126 and SF767 cell lines. LRRC4 mRNA expression in SF126 and SF767 cell lines treated by 5-Aza-CdR was detected by RT-PCR. In addition, the effect on glioma cell lines cell growth and cell cycle of 5-Aza-CdR were assayed by MTT and FCM. The results indicated that LRRC4 promter was completely methylated in SF126 and SF767 cells. However, LRRC4 promoter aberrant hypermethylation can be reversed and LRRC4 expression can be induced by 5-Aza-CdR. Moreover, 5-Aza-CdR displayed a growth inhitory effect on SF126 and SF767 cells in a dose- and time-dependent manner after exposure to 5-Aza-CdR at different concentration for different time. FCM analysis showed that SF126 and SF767 cells cell cycles were blocked at G0/G1 phase after 5-Aza-CdR treatment for three days. Taken together, glioma cell lines SF126 and SF767 cell growth could be inhibited and cell cycles could be blocked by 5-Aza-CdR; promoter hypermethylation is the important mechanism of LRRC4 inacctivation in glioma cell lines; methylation can be reversed and LRRC4 expression can be induced by 5-Aza-CdR. All this suggest that LRRC4 may serve as a demethylation therapeutic target in glioma.