Objective to observe plasma Brain Natriuretic Peptide level by use of low dose Betaloc for congestive heart failure.Methods We chose 31 heart failure patients with Ⅲ～Ⅳ New York Heart Association (NYHA)functional classification,and used low dose Betaloc on the basis of traditional treatment,then observed the changement of plasma Brain Natriuretic Peptide level during treatment. Results After treatment,patients' heart rate, blood pressure ,cardio-thoracic ratio and LVDd all descended,but LVEF increased.The value of BNP declined obviously,after the use of the Betaloc.Conclusions We treated congestive heart failure with low dose Betaloc,the availability ratio was more than 80%,and the value of BNP declined obviously.It implied dynamic monitoring plasma Brain Natriuretic Peptide was helpful in understanding treatment effect and prognosis.