Abstract: Objective: To investigate the application value of furosemide guided by lung ultrasound in the treatment of acute left heart failure. Methods: Seventy patients with acute left heart failure were randomly divided into the observation group(36 cases) and control group(34 cases). The control group were empirically treated with furosemide, the observation group were treated with furosemide guided by lung ultrasound. The total required diuretics, maximum daily urine amount and the decreasing degree of B-type natriuretic peptide after treatment between two group were compared. Results: The total required furosemide in observation group was less than that in control group(P<0.01). The differences of maximum daily urine amount and the decreasing degree of B-type natriuretic peptide after treatment in two groups were statistically significant(P<0.01). Conclusions: Lung ultrasound can evaluate the therapeutic effects of furosemide in patients with acute left heart failure, guide the treatment of acute left heart failure, and reduce the use amount of furosemide.