Aim: To study the effect of Rhodiola rosea injection on cardiac function and the reninangiotensin-aldosterone system (RASS) in rats with chronic heart failure. background: Rhodiola rosea injection, a traditional Chinese medication for relieving blood stasis and improving blood circulation, is an excellent therapeutic for treating coronary heart disease—angina pectoris. Rhodiola rosea injection's major component, salidroside, protects the cardiovascular system. But there isn't much first-hand evidence about how injectable Rhodiola rosea affects heart failure. Background: Rhodiola rosea injection, a traditional Chinese medication for relieving blood stasis and improving blood circulation, is an excellent therapeutic for treating coronary heart diseaseangina pectoris. Rhodiola rosea injection's major component, salidroside, protects the cardiovascular system. But there isn't much first-hand evidence about how injectable Rhodiola rosea affects heart failure. objective: In this study, a rat model of heart failure was established, and the effect of Rhodiola rosea injection on myocardial cell morphology, cardiac function, and ventricular remodelling in rats with heart failure was investigated. The influence and significance of miRNA210-3p expression provide basic research data support for Rhodiola rosea injection in the treatment of heart failure and provide a strong basis for clinical off-label drug use. Objectives: In this study, a rat model of heart failure was established, and the effect of Rhodiola rosea injection on myocardial cell morphology, cardiac function, and ventricular remodelling in rats with heart failure was investigated. method: 66 SD male rats were selected; 10 were randomly selected as a blank control group, and the remaining 56 rats were injected intraperitoneally with doxorubicin (4 μg/g), and cardiac function was measured in all rats after 6 weeks, with LVEF 60%. A successful heart failure model was established. The model rats were randomly divided into four groups: model control group, low-dose group, medium-dose group, and high-dose group of Rhodiola rosea injection, with 14 rats in each group. The 2mL/kg of Rhodiola rosea injection was injected into the tail vein once a day for 2 consecutive weeks. The blank group and the control group were given the same amount of normal saline every day. After 2 weeks, the echocardiographic index, RASS-related index, and serum BNP level were measured in all rats, and the morphology of myocardial tissue was observed by hematoxylin-eosin staining. The peripheral blood was collected to extract plasma miRNA423-5p, miRNA499-5p and miRNA210-3p. Compared with healthy control rats, the effect and significance of Rhodiola rosea injection on its expression were investigated. Methods: 66 SD male rats were selected; 10 were randomly selected as a blank control group, and 56 were treated intraperitoneally with doxorubicin (4 g/g). After 6 weeks, all animals had LVEF 60%. Established a heart failure model. Each group had 14 rats: model control, low-dose, mediumdose, and high-dose Rhodiola rosea injection. The 2mL/kg of Rhodiola rosea injection was injected into the tail vein once a day for 2 weeks. Both the blank and control groups received normal daily saline. After 2 weeks, the echocardiographic index, RASS-related index, and serum BNP level were assessed in all rats, and myocardial tissue morphology was observed. MiRNA423-5p, miRNA499-5p, and miRNA210-3p were extracted from peripheral blood. Rhodiola rosea injection on its expression was compared to healthy control rats. Results: 6 mL/kg Rhodiola rosea injection lowered LVEDV and LVESV while increasing LVEF and LVFS. Injections of 6 mL/kg Rhodiola rosea reduce plasma levels of miR-210-3p, miR-423- 5p, miRNA-499, and BNP in heart failure model rats. The 6 mL/kg Rhodiola rosea injection can restore the RASS indexes of heart failure rats to the level of the normal group. Conclusion: The present study offers preliminary evidence supporting the use of Rhodiola rosea injection in the treatment of heart failure and offers a solid foundation for clinical off-label medication use. other: N/A