Abstract: Objective: To observe the plasma brain natriuretic peptid(BNP)levels of hemodialysis(HD)patient before and after adjustment of dry weight and explore its value in evaluating dry weight.Methods: Fifty HD patients were divided into group A(noreaching the dry weight standard,25 cases)and group B(reaching the dry weight standard,25 cases)according to the dry weight evaulated by cardiac thoracic rate(CRT),blood pressure,body weight and the inferior vena cava width(IVCD).The dry weight of partial patients from group A were adjusted to reach the clinical dry weight by increasing the dialysis dehydrated level for 4 weeks, which was divided into group D.Twenty-five healthy persons were divided into group C(control group),which blood pressure,CRT, VCD and BNP were measured.Results: The levels of BNP,CRT and VCD of group A were significantly higher than that of group B,C and D(P＜0.01), and there were no significant difference between the BNP levels of group B,C and D(P ＞ 0.05).BNP level changes of group A before and after adjustment of dry weight were positively related to its value of VCD and CRT(P＜0.01).Conclusions: BNP can be used as the water load index of HD patients,which has a certain value to assess dry weight.