Abstract: Objective: To explore the evaluation effect of cardiopulmonary ultrasound (CPUS) on the progression and efficacy of doxorubicin (DOX)-induced heart failure (HF) rats. Methods: Eighty-eight SD rats were randomly divided into three groups: control group (n=8), model group (n=48, intraperitoneal injection of DOX, twice a week), and treatment group (n=32, 6 weeks after DOX injection, Qili Qiangxin Capsules were given intragastric administration, once a day). The model group was divided into 6 subgroups with 8 rats in each group according to the duration of DOX injection (1-6 weeks). The treatment group was divided into 4 subgroups with 8 rats in each group according to the duration of intragastric administration (1-4 weeks). CPUS and histopathological examination were performed in all groups. Results: Compared with the control group, the left atrioventricular chamber in the model group enlarged; the left atrial diameter (LAD) at the end of the contraction, the ratio of left atrial diameter to right atrial diameter (LAD/RAD) at the end of the contraction, and the ratio of left ventricular end-diastolic diameter to right ventricular end-diastolic diameter (LVEDD/RVEDD) were all higher than those in the control group; the E/e’values of both the left and right ventricles were increased; the left ventricular ejection fraction (LVEF) and the tricuspid annular plane systolic excursion (TAPSE), and the left ventricular wall thickness (LVWT) were decreased (all P＜0.05). In the model group, the pleural line and A-lines were blurred or disappeared, the number of B-lines was increased, and the lung ultrasound score (PLUS) was higher than that of the control group. HE staining showed that the histopathological changes in the heart of the model group were myocardial cell degeneration and edema, with disordered myocardial fiber arrangement, interstitial edema and porosity, and inflammatory cell infiltration. The histopathological changes in the lung tissue were destruction of alveolar structure, thickening of lobular septa, effusion in alveolar cavity, congestion of alveolar capillaries, and inflammatory cell infiltration, which were consistent with the histopathological changes of heart and lung in HF. In the treatment group, the left atrioventricular chamber was decreased, LAD and LVEDD/RVEDD were lower than those in the model group (P＜0.05), while there was no statistically significant difference in LAD/RAD (P＞ 0.05). The systolic and diastolic functions of the left and right ventricles were improved, LVEF and TAPSE were higher than those in the model group , and the E/e’values of both the left and right ventricles were lower than those in the model group (P＜0.05). LVWT was higher than that in the control group, while RVWT was lower than that in the control group (P＜0.05). The lung ultrasound showed a decrease in the number of B-lines, and Alines were visible. Compared with the model group injected for 6 weeks, the PLUS score of the treatment group was significantly lower after 3 and 4 weeks of injection (P＜0.05), and the pathological morphology of the heart and lung gradually improved with the extension of the administration time. There was a significant correlation between cardiac ultrasound parameters and PLUS. LAD and LVEDD/RVEDD were positively correlated with PLUS, while LVEF and TAPSE were negatively correlated with PLUS (P＜0.001). Conclusion: CPUS can dynamically monitor the disease progression of HF rats, evaluate the effectiveness of intervention and treatment, and closely track the progression of the disease, which is expected to provide effective monitoring methods for basic research and clinical treatment of HF.