Diabetic retinopathy (DR) is a highly specific vascular complication of type 1 and type 2 diabetes mellitus. Calcium dobesilate(CD) or Doxium has been tested in the treatment of diabetic retinopathy showing a slowdown of the progression of the disease after long-term oral treatment,as a potent antioxidant. Endothelin-1 (ET-1) Besides being a very potent vasoconstrictor,acts as a mitogen on the vascular smooth muscle and play the main role in the failure of autoregulation that it is an important and often early feature of diabetic retinopathy.several studies have been confirmed that inflammation besides oxidative stress are the main mechanisms,in the pathogenesis of DR and hsCRP can play a sensitive role in detecting inflammation in these patients. The aim of this study was to determine the effects of CD on decreasing ET-1 and hsCRP serum levels in patients with diabetic retinopathy.