Abstract: Objective To study the effect of hemodiafiltration on micro-inflammation and nutritional status in maintenance hemodialysis patients.Methods A total of 300 terminal renal disease(ESRD) patients with hemodialysis were randomly divided into HDF group(n =150) and HD group(n =150).The blood of serum albumin(Alb),total protein(TP),hemoglobin(Hb),high-sensitivity C-reactive protein (hs-CRP),interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels were determined by a biochemistry analyzer before and after 12 weeks of treatment.Results No significant differences was seen in hs-CRP,IL-6,TNF-α,TP,ALB and Hb between two groups before treatment(P ＞ 0.05).However,hs-CRP,IL-6 and TNF-α significantly decreased after the treatment in HOF group(P ＜0.01) but not in HD group.TP,ALB and Hb significantly increased after the treatment in the 2 groups (P ＜ 0.05).After the treatment,TP,ALB and Hb were higher in HOF group than in HD group (P ＜ 0.05),and hs-CRP,IL-6 and TNF-α were lower in HDF group than in HD group(P ＜ 0.05).Conclusion HDF can effectively clear the macromolecules inflammatory cytokines,alleviate the micro-inflammatory state,and improve nutritional status of MHD patients.