Objective: To analyze the relationship between the patient’s ECG QRS complex duration, serum sST2 and prognosis, and the influencing factors of fragmented QRS complex formation. Methods: A total of 106 patients with coronary heart disease admitted to the Second Afliated Hospital of Soochow University from June 2019 to June 2020 were divided into angina pectoris group, myocardial infarction group, and heart failure group according to the disease progression. Fifty healthy subjects served as the control group. The time limit of sST2 and QRS wave in the blood were detected; the logistics regression model was used to analyze the factors forming fQRS. Results: The QRS wave duration and sST2 of the coronary heart disease group were significantly higher than those of the control group, and the difference was statistically significant (P<0.05). There were significant differences in QRS wave duration and sST2 levels in the angina pectoris group, myocardial infarction group, and heart failure group. And the difference was statistically significant (P<0.05). The QRS duration and sST2 level of patients in the central failure group were the highest, and the angina group was the lowest; QRS duration and sST2 levels were positively correlated with the disease progression (P<0.05); the total cholesterol, the number of lesions and Gensini score in the fQRS group were significantly higher than those in the non-fQRS group, and the high-density lipoprotein level was significantly lower than that in the non-QRS group, and the difference was statistically significant (P<0.05); the number of lesions, Gensini score and low high density lipoprotein were independent risk factors for the formation of fQRS (P<0.05). Conclusion: There is a positive correlation between the ECG QRS wave duration and serum sST2 in patients with coronary heart disease and the severity of the patient's condition. The number of coronary artery lesions and the level of Gensini score are independent factors that affect the appearance of fQRS in patients.