Aim To investigate whether disturbed flow affects endothelial cell function and atherosclerotic plaque formation by regulating histone demethylase KDM5B and epigenetic modification. Methods After partial carotid artery ligation (PCL), single-cell data analysis and immunofluorescence staining were used to investigate the changes of histone methylation level and histone demethylase expression in carotid endothelial cells of wild type mice under perturbed flow. qPCR and Western blot were used to detect the expression of KDM5B and H3K4me3 in endothelial cells exposed to disturbed flow. Transcriptome sequencing was used to analyze the effect of KDM5B knockdown on endothelial cell function.Endothelial cell ring formation assay was used to verify the effect of KDM5B on angiogenesis. PCL combined with high-fat diet for 2 weeks was used to establish a carotid artery plaque model to analyze the effect of KDM5B knockdown on plaque formation. Results There was a large amount of H3K4me3 methylation in vascular endothelial cells. Blood disturbed flow reduced the methylation of H3K4me3 (P＜0.01) and promoted the expression of histone demethylases KDM5B in endothelial cells (P＜0.05). Compared with control group, inhibition of KDM5B activity or knockdown of KDM5B increased H3K4me3 level in endothelial cells (P＜0.05). Compared with Con313 control group, KDM5B knockdown reduced atherosclerotic plaque formation by 41.45% (Con313 control group:42.17%±1.90%, shKDM5B knockdown group:24.69%±1.60%, P＜0.01) by inhibiting angiogenesis. Conclusions Blood disturbed flow promotes KDM5B expression, reduces H3K4me3 modification, and promotes angiogenesis and atherosclerotic plaque formation. Targeting the KDM5B-H3K4me3 axis can be used as a candidate therapeutic target related to cardiovascular diseases.