Henoch-$Sch{ddot{o}}nlein$ purpura(HSP) frequently follows upper respiratory infection, and one of the causes of this discase is inferred to $eta$-hemolytic streptococcal infection, but the relationship is still unclear. familial tendency of this disease is unclear, too. Also genetic relationship of this disease has been in a controversy yet. We experienced two cases of HSP in brother and sister at similar period, and report this case with review of related literatures.