The continuous lymphoblastoid cell lines KMPG-1 and SPG-2 producing baboon herpes virus (HVP) with morphological signs of herpes viruses have been established from haematopoietic organs of lymphomatous baboons. As distinct from H.simplex type I and II viruses HVP is not pathogenic for laboratory rodents. According to its physico-chemical and immunological properties HVP is related to the Epstein-Barr virus.