The sprouting of endothelial cells is the first step of tumor angiogenesis. Our previous study suggests that miR-153 suppressesbreast tumor angiogenesis partially through targeting hypoxia-induced factor (HIF1α). In this study, we demonstrated thatmiR-153 also suppresses the migration and the tube formation of endothelial cells through directly targeting angiopoietin 1(ANG1) in breast cancer cells. There was a negative correlation between miR-153 and ANG1 levels in breast cancer. miR-153blocked the expression and secretion of ANG1 in breast cancer cells through binding to ANG1 mRNA. Conditioned mediumfrom the breast cancer cell, MCF7, treated with miR-153 had no effect on the proliferation of HUVECs, but significantlyinhibited the migration and tube formation of HUVECs, which could be rescued by overexpression of ANG1. In addition,miR-153 also directly inhibited the proliferation and migration of MCF7 through downregulation of ANG1. These findingssuggest that miR-153 suppresses the activity of tumor cells and the migration and tube formation of endothelial cells bysilencing ANG1.