Objective To study the role of TLR2 in AngⅡ-induced cardiac fibrosis in hypertensive mice .Methods Eighteen wild C57 mice were randomly divided into blank control group ,AngⅡgroup and TLR2 blocking group (6 in each group) .A hypertension model was established by sub-cutaneous infusion of AngⅡthrough a mini-pump for 7 days .Cardiac fibrosis in mice was observed with immunohistochemical staining .Results The area of cardiac fibrosis was significantly larger and the expression levels of collagen Ⅰ and TGF-βwere significantly higher in Ang Ⅱgroup than in blank control group (P<0 .05) .The area of cardiac fibrosis was 71 .2% smaller ,the expression level of collagen Ⅰ was 75 .5% ,and the expression level of TLR2 was 77 .7% lower in TLR2 blocking group than in Ang Ⅱgroup (P<0 .05) .Conclusion TLR2 is involved in Ang Ⅱ-induced cardiac fibrosis in hypertensive mice .