By use of pentobarbital sodium to produce experimental congestive heart failure (CHF) in 40 rabbits, they were treated with xin-fu-ning IV (XFN IV), the plasma atrial natriuretic factor (ANF) levels and atrial tissue ANF levels of rabbits were measured. The results showed that XFN IV had elevated ANF levels of the rabbits with CHF. It showed that XFN IV could improve endocrine function of heart, and it also showed good curative effect on CHF.