Henoch-Schonlein purpura (HSP) is an IgA-mediated disorder that most commonly occurs in children. Its etiology and pathogenesis remain unknown. In recent years, numerous studies have pointed to a dysfunction of T cells in the pathogenesis of HSP. Here, we will review the epidemiology, clinical and molecular characteristics of HSP, as well as abnormalities of Th cell subsets in this disorder. Finally, we will discuss the key factors that are involved in Th cell differentiation as potential novel targets for the prevention and treatment of HSP.