Cataract is the first blinding eye disease in China and the main cause of blindness in most countries in the world. Currently, surgery operation is the only effective treatment. Posterior capsular opacification(PCO)is a common complication after cataract surgery, and it is also the crucial induction of vision decline. Studies have shown that epithelial-mesenchymal transition(EMT)of lens epithelial cells(LECs)remaining after surgery plays an important role in the occurrence and development of PCO. This article mainly summarizes the research progress of EMT in PCO in recent years.