IL-7 receptor (IL-7R) plays critical roles in lymphocyte development by promoting survival and proliferation and by inducing V(D)J recombination in TCR and Ig loci. Here, we demonstrate that IL-7R-activated Stat5 binds to consensus motifs in the 5' regions of Jγ segments and induces germline transcripts. We also show that a constitutively active form of Stat5 restores V-J recombination of TCRγ genes and partially rescues T cell development from IL-7R - / - T cell precursors, especially in favor of γδ T cells. Therefore, this study reveals a potential role of Stat5 in T cell development and also implies that IL-7R may control the accessibility of the TCRγ locus through Stat5-induced germline transcription.