Objective To investigate the effect of on-line hemodiafiltration in the treatment of delayed graft function. Methods One hundred and fourteen times of on-line hemodiafiltration treament were performed on 29 patients and 68 times hemodialysis were performed on 9 patients. Results Twenty-nine patients undergoing hemodiafiltration had shorter period for graft function recovery than that of the 9 patients undergoing hemodialysis.(11.2±5.6d vs 22.3±15.7d, P<0.05). Hypotension occurred in 13.2% patients receiving hemodialysis while 2.6% patients receiving hemodiafiltration(P<0.05). Conclusion Compared with hemodialysis, on-line hemodiafiltration has less influence on blood pressure than hemodialysis and may shorten graft function recovery time. 