Abstract: Objective To investigate the gene expression of methyl-CpG-binding protein 2 （MeCP2） and methyl-CpG-binding domain 2 （mbd2） in patients with systemic lupus erythematosus（SLE） and their significance in the pathogenesis of SLE. Methods Semiquantitative reverse transcriptase-PCR was applied to detect the mRNA expression of MeCP2 and mbd2 in PBMCs obtained from relieved （n = 17）, active （n = 17） SLE patients and healthy controls （n = 17）. The correlations were further analyzed among these parameters. Results No significant difference was observed in the expression level of MeCP2 mRNA among active SLE patients, relieved SLE patients and healthy controls （P > 0.05）. The expression of mbd2 in relieved SLE patients was significantly higher than that in health controls （t = 12.8, P < 0.01), but lower than that in active SLE patients（t = 20.0, P < 0.01）. The expression of mbd2 positively correlated with SLEDAI （r = 0.737, P = 0.0001） of patients with SLE, and a positive correlation was also observed between the expression of mbd2 and MeCP2 in healthy controls（r = 0.550, P = 0.0222）. Conclusions The expression of MeCP2 and mbd2 may be mutually constrained in normal human, but this relationship seems to be disturbed in patients with SLE.