The Notch pathway is a wildly utilized, evolutionarily conserved regulatory signaling pathway that plays a central role in the fate decisions of multipotent precursors including common lymphoid precursors, which will undergo either T or B cell differentiation. Notch signaling participates in the process of lymphocyte development. It can promote formation of Tαβ cells, induce development of regulatory T cells from na?ve T cells, and block CD4+ T cell to differentiate to Th1 cell. It can increase the numbers of MZB cells. On the basis of structure of Notch and the new progress on Notch, the role of Notch signaling in the process of lymphocyte development and its molecular mechanisms have been reviewed.