The posterior capsule opacification(PCO)is one of the most mainly common complications after modern cataract surgery. Smad proteins family are important factors of intracellular TGF (transforming growth factor)-β signaling transduction. TGF-β/Smads signalling pathway is very important for PCO, especially all kinds of Smads are being close relationship with PCO in induction of TGF-β2.This article reviewed the relationship between TGF-β/Smads and PCO.