ObjectiveTo observe the changes of transforming growth factor-β（TGF-β）and B-cell lymphoma-2（Bcl-2）protein expression in vulva skin tissue of rats treated with focused ultrasound

and to explore the mechanism of action offocused ultrasound in the treatment of lichen simplex chronicus（LSC）.MethodsForty female SD rats with LSC were randomlydivided into experimental group and control group

with 20 rats in each group.The rats in the experimental group were treatedwith focused ultrasound

while the control group were treated with focused ultrasound false irradiation.Another 10 normal SD ratswere selected as the blank control group.After 4 weeks of focused ultrasound treatment

the recovery of vulva skin was observedand compared between the experimental group and the control group.Masson staining was used to identify the density of collagenfibers in the superficial dermis of rats in each group.The expression of TGF-β and Bcl-2 protein in vulva skin tissue weredetected by immunohistochemistry and Western blotting.The density of collagen fiber in superficial dermis and the expression ofTGF-β and Bcl-2 protein in vulva skin tissue were compared.ResultsIn experimental group

70%（14/20）experimental ratsreturned to normal.In control group

only 10%（2/20）returned to normal.The difference of cure rate between the two groups wasstatistically significant（P<0.05）.The density of collagen fibers in the superficial dermis of the experimental group and blank control group were significantly higher than that of control group（both P<0.05）

while there was no significant difference betweenexperimental group and blank control group.The expression of TGF-β protein in vulvar tissues of experimental group and blankcontrol group were significantly lower than that of the control group

while the expression of Bcl-2 protein were higher than thatof the control group（all P<0.05）. There was no significant difference between experimental group and blank control group.ConclusionFocused ultrasound may effectively treat rats with LSC by affecting the expression of TGF-β and Bcl-2 protein invulva skin tissue.