Objective To observe the effect of demethylating agent 5-aza-2 "-deoxycytidine (5-Aza-CdR) on pericyte-myofibroblast transition(PMT)of primary rat renal myofibroblast. Methods Rat primary renal myofibroblast were treated with 5-Aza-CdR 250 ng/ml for 72h, and the methylation degree of Epo promoter was detected by pyrosequencing. The protein expression levels of α-SMA, PDGFRβ and DNA methyltransferase (DNMT3a) were detected by immunofluorescence and Western blot, and EPO levels in the supernatant were detected. Results Compared with control group, 5-Aza-CdR treatment significantly decreased the expression of Dnmt3a and the hypermethylation level of Epo promoter, and subsequently decreased the expression of α-SMA and the expression ratio of α-SMA to PDGFRβ in myofibroblast. Meanwhile, 5-Aza-CdR treatment increased the level of EPO in the cell supernatant. Conclusions 5-Aza-CdR can reverse PMT by inhibiting Epo promoter hypermethylation in primary renal myofibroblast.