Objective:To investigate the effects of TGF-? 1 and TGF-? 2 on cleft palate formation .Methods:30 pregnant NIH mice in experimental group were injected with dexamethasone (50 mg/kg) intr aperitoneally in GD 12 12 ,30 mice in control group were given the same vo lume of NS.Fetuses were removed out in GD13 12 ,GD14 12 and GD15 12 , heads of the mice were sliced in coronal plane.Expression of TGF-? 1 an d TGF-? 2 in embryonic palate were detected by immunohistochemical methods: Results:Dexamethasone (50 mg/kg) induced cleft palate in NI H embryos,and expression of TGF-? 1 and TGF-? 2 in palate tissues was h igher in the experimental group than that in the control (P