AIM:To observe the structure changes of sclera and determine the expression of TGF-β2 in the sclera of the model.METHODS:A facemask was worn on the right eyes of guinea pigs to develop form deprivation myopia.Before and after experiment,refraction was measured using retinoscope,and the ocular axial was determined by A-scan ultrasonography.Morphologic alterations of the posterior sclera were observed by light microsope.The expression of TGF-β2 in the posterior sclera was determined by immunohistochemistry.RESULTS:Posterior sclera of myopic eyes became thinner,and collagen fibres were disordered,fibers diameters were dissimilarity,the space between the fibres was larger,the parallel structure was illegible.The immunohistochemisty showed that expression of TGF-β2 in model eyes were lower than control eyes(P<0.05).CONCLUSION:Covering eyes with facemasks is effective,simple and convenient in making myopic model.The sclera of the model eye appeared degeneration.TGF-β2 plays an important role in the course of development in form deprivation myopia.