Abstract: Notch signaling pathway is a highly conserved signaling pathway,and plays an important role in the individual growth and development process in the vertebrate.Many studies have demonstrated Notch3 receptor expression is aberrant in a variety of tumors.Recent studies show that aberrant Notch3 mediated signaling pathway is closely related with the progression of diverse types of tumors.Notch3 plays a vital role in apoptosis,proliferation and differentiation of tumor cells.To promote the studies of Notch3 as a drug development targets,the molecular mechanisms of abnormal Notch3 expression and its role on tumorgenesis,progression and treatment resistance are reviewed in this paper.