Objective To investigate the curative effect of large doses of recombinant human B-type natriuretic peptide(rhBNP)on acute refractory heart failure. Methods 50 patients with acute severe refractory heart failure were randomly divided into two groups and treated with priming loading dose of 1.5 μg/kg intravenous injection of rhBNP, and then 23 patients in low doses group maintained the therapy for 48 to 72 hours with the speed of 0.01 μg/(kg·min),while 27 patients in high doses group maintained the therapy for 24 hours with the speed of 0.03 μg/(kg·min) and following dose of 0.015 g/(kg·min)for continuous 24 to 48 hours.The changes of clinical symptoms and physical signs in both groups were observed,and the changes of urinary volume during 24 hours,renal function,NT-proBNP in both groups were recorded,30 d mortality and rehospitalization rates were also recorded. Reaults The high doses group had a more significant improvement of clinical symptoms during 24-48 hours, urinary volume, and NT-proBNP than the other one (P＜0.05).The clinical symptoms in 7 days,the change of creatinine, mortality and rehospitalization rates had no differences between the two groups(P＞0.05). Conclusions Intravenous injection of large doses rhBNP improves clinical symptoms, urinary volume and NT-proBNP,but has no effect on renal function, mortality and rehospitalization rates.