Objective To evaluate the expression of TGF? 1 in rat testes after vas deferens ligature and release again. Methods Ninety rats were randomized into 3 groups:vas deferens ligature in 35 rats,release again after ligature in 20,sham-operation in 35.Immunohistochemical staining and hybridization in situ were used to detect the expression of TGF? 1. Results The expression of TGF? 1 in vas deferens ligature group was higher than that in sham-operation group after 8 weeks ( P