Objective. This study was to investigate the effects of transforming growth factor-β（TGFβ） and fi- broblast growth factor （FGF） in the subcapsular opacification formation of the lens. Methods. Lens epithelial explants from 10-day-old rats were cultured with TGFβ1 or TGFβ2 in the presence of FGF for 5 days

then were examined by light and electron microscopy

and by immunolocal- ization of smooth muscle（α-sm） actin and type I collagen. Results. In TGFβ/FGF-treated explants

extensive proliferation occured

with formation of spindle and star-shaped cells. These cells showed ultrastructure and biochemical features of fibroblast or myofibroblast. Prominent Golgi apparatus and rough endoplaic reticulum were observed in some cells. Intracellular micro- filaments with cytoplasmic dense babies and membrane associated dense bodies

features of smooth muscle cells

were also observed. Some cells showed reactivity to -sin actin antibody. TGFβ/FGF-treated ex- plants were strongly stained with type I collagen antibody. Condusion. In the presence of FGF

TGFβ1 and TGFβ2 induced lens epithelial cell （LEC ） proliferation and transformation into fibroblast or myofibroblast-like cells

with producing of abundant collagen matrix in the explants. The changes are similar to the metaplasia that occurrs in subcapsular opacification of the lens. The findings suggest that TGFβ and FGF plays a role in the pathogenesis of subcapsular opacification of the lens.