Abstract: Objective To investigate the relationship between ambulatory blood pressure variability and coronary heart disease as well as its severity. Methods A total of 368 participants who underwent coronary angiography and ambulatory blood pressure monitoring from March 2021 to November 2022 were consecutively included, and 38 patients with acute myocardial infarction were excluded. According to the angiography results, the participants were divided into coronary heart disease（CHD） group（n=156） and non-CHD group（n=174）. The general basic clinical data, laboratory indicators and ambulatory blood pressure parameters of patients between the two groups were compared. Multivariate logistic regression analysis was conducted to screen out independent risk factors for predicting CHD, which were used to construct an nomogram to predict the occurrence of CHD. The receiver operating characteristic（ROC） curve was drawn to evaluate the differentiation of the models, and the prediction model constructed by the nomogram was verified by Bootstrap method. Restricted cubic spline（RCS） was used to investigate the nonlinear relationship between 24-hoursystolic blood pressure average real variability（24hSARV） and the degree of coronary artery disease. Results Compared with non-CHD group, the age and proportion of male, diabetes and β-blocker used, 24 hours as well as daytime and nighttime systolic blood pressure, 24 hours as well as daytime and nighttime SARV, and nighttime standard deviation of diastolic blood pressure were significantly increased in CHD group（all P＜0.05）. Multiple logistic regression suggested that gender, age, β-blocker used and 24h SARV were independent risk factors for CHD（P＜0.05）. The area under the ROC curve（AUC） of the nomogram containing the above four indicators was 0.707（95%CI 0.651-0.763）. The calibration curve indicated that the trajectory of the correction curve basically coincided with that of the ideal curve. RCS indicated that the 24hSARV had an inverted L-shaped correlation with the severity of coronary artery lesions. With the increase of Gensini score, the 24hSARV gradually increased and then stabilized（P=0.005）. Conclusion Twenty-four-hour SARV is significantly increased in patients with CHD, it is an independent risk factor for CHD and can predict the degree of coronary artery stenosis.