Objective To study the effect of high flux dialysis on of left ventricular structure and function maintenance hemodialysis patients and its mechanism. Methods A total of 55 hemodialysis patients were divided into two groups: high flux hemodialysis (HPD) group, treated with Fresenius F60 polysulfone dialyzer; conventional hemodialysis (CHD) group, treated with Fresenius F6 polysulfone dialyzer. Before and after the treatments, blood urea nitrogen(BUN), creatinine(Cr), potassium, sodium, chloride, calcium, phosphorus, parathyroid hormone(PTH)，echocardiography and Hb, hematocrie(Hct) were measured. At the same time, the levels of serum cytokines(IL-1β, IL-6, IL-8, TNF-α)were determined by radioimmunoassay, and the levels of cytokine in dialysate were also detected. After one year, all index were remeasured. Results The clearance of serum phosphorus, PTH were significantly higher in HPD group than that in CHD group (P＜0.05). The left ventricular mass and left ventricular end diastolic volume were decreased after hemodialysis, while there were no significant difference between HPD group and CHD group. But after one year, there were significant differences between the two groups. Conclusions Hemodialysis can improve left ventricular diastolic and systolic function in patients with maintenance hemodialysis, HPD can improve them more effectively. Possible mechanism may be correlated with the clearance of midde molecular substances suchas PTH,(PTH), cytokine and improving of renal anemia.