Abstract: Objective To study the effects of blood pressure variability（BPV） and plasma homocysteine（Hcy） on carotid atherosclerosis in H-type hypertensive patients. Methods A total of 287 essential hypertensive patients were enrolled from January 2015 to December 2018, and 55 normal blood pressure individuals were included in control group. Routine biochemical indexes, plasma Hcy level, 24-hour ambulatory blood pressure（ABP） were collected and color Doppler ultrasound was performed in all subjects. Then according to the level of plasma Hcy, all essential hypertensive patients were divided into two groups, including normal Hcy hypertensive group（NH group, Hcy＜15 μmol/L, n=212） and high Hcy hypertensive group（HH group, Hcy≥15 μmol/L,n=75）. Pearson correlation analysis, factorial design variance analysis, multivariate stepwise linear regression analysis and binary logistics regression were used to analyze the relationship between Hcy, BPV and intima-media thickness（IMT）. Results Compared with normal blood pressure group, the office blood pressure, ABP, the standard deviation of 24 hour systolic blood pressure（24 hSSD）, the standard deviation of daytime systolic blood pressure（dSSD）, the standard deviation of nighttime systolic blood pressure（nSSD） in the HH group and NH group were all increased（all P＜0.05）. Compared with the NH group, the level of plasma Hcy, urea nitrogen, serum creatinine, office systolic pressure, 24 hSSD were higher in the HH group（P＜0.05）. IMT in HH group was higher than that in NH group, and the IMT of the two groups were higher than that of control group（1.03±0.19） vs（0.89±0.18） vs（0.78±0.17） cm, F=31.169, P＜0.001. The factorial design variance analysis showed that high Hcy（F=5.213, P=0.023） and high office blood pressure（F=8.153, P=0.005） had an impact on IMT, but there was no interaction and synergy between them（F=0.361, P=0.548）. The Pearson correlation analysis showed that IMT in patients with hypertension was positively correlated with plasma Hcy（r=0.298）, 24 hSSD（r=0.207）, 24-hour systolic blood pressure variation coefficient（24 hSCV）（r=0.172）, dSSD（r=0.210）, daytime systolic blood pressure variation coefficient（dSCV）（r=0.186）, nSSD（r=0.199）, nighttime systolic blood pressure variation coefficient（nSCV）（r=0.161）（all P＜0.05）. And IMT was negatively correlated with 24-hour diastolic blood pressure（24 hDBP）（r=-0.127） and daytime diastolic blood pressure（dDBP）（r=-0.144）（all P＜0.05）. Multiple stepwise linear regression showed that age（β=0.282）, Hcy（β=0.251）, dSSD（β=0.147） had influence on IMT（all P＜0.05）, but the effects gradually diminished. The binary logistic regression analysis showed that Hcy and 24 hSSD（OR=1.009）, 24 hSCV（OR=3.317）, 24-hour diastolic blood pressure variation coefficient（24 hDCV）（OR=2.122）, dSSD（OR=1.010）, dSCV（OR=3.515）, daytime diastolic blood pressure variation coefficient（dDCV）（OR=2.128）, nighttime diastolic pressure（nDBP）（OR=1.001）, nSSD（OR=1.009）, nSCV（OR=3.101）, nighttime diastolic blood pressure variation coefficient（nDCV）（OR=1.978） had a synergistic effect on IMT（P＜0.05）, among which, Hcy and the coefficient of variation of blood pressure had more significant effects on IMT. Conclusions High level of serum Hcy and BPV are risk factors of carotid atherosclerosis in hypertensive patients, Hcy and BPV have synergistic influence on carotid atherosclerosis in hypertensive patients.