Abstract： Objective To observe the effect of intravitreal injection of bevacizumab(Avastin,IVB)on the expression of integrin-linked kinase(ILK)in fibrovascular membranes and the number of vascular endothelial cells(VECs)in proliferative diabetic retinopathy(PDR).Methods Twenty-four fibrovascular membrane samples were collected during pars plana vitrectomy in 24 patients with PDR.1 2 PDR patients had received a single 1.25 mg IVB 7 days preoperatively(bevaeizumab group),the other 1 2 patients(nonbevacizumab group)had not received lVB.For each of 24 fibrovascular membranes specimen.the number of VECs in the membranes were counted after staining with hematoxylin-eosin and yon willebrand factor.Expressions of ILK in the fibrovascular membranes were detected through immunohistochemistry analysis.Results Immunohistochemistry revealed that ILK was highly expressed in all of 24 fibrovaseular membranes of PDR.The average optieal density of ILK expression level in bevacizumab and non-bevaeizumab group were(127.78±15.08)and(129.03±16.26)respectively.the difference was not statistically significant (t=0.330,P=0.745).The number of VECs in ftbrovascular membranes in bevacizumab and nonbevaeizumab group were 21.50±3.94 and 41.33±7.44 respectively,the difference was statistically significant(t=3.872,P=0.003).Condusiom ILK was expressed in fibrovascular membranes of PDR.IVB can decrease the number of VECS during the process of PDR,but it can not affect the expression of ILK protein.