Signal transducer and activator of transcription(STAT)3 is a member of the cytoplasmic transcription factors family which participates in a wide variety of physiological processes including cell growth, differentiation, proliferation, apoptosis and angiogenesis. It broadly exists in various tissues as well as retina. The expression of STAT3 plays an important role in various retinal diseases including ischemic retinopathy, diabetic retinopathy. The purpose of this paper is to review the biological functions of STAT3, and its role in various.