Through the recent study, we have come to know that the gene group, which has an important function, is closely existed in the part of 6 chromosome short arm of a human being. Gene group consists of a major histocompatibility complex which develops rejective reaction in the process of kidey tranplantation, the gene group which controls immune response and the gene group which decides serum compliment component. These are called HLA in total. Through HLA-a.B.C. typhing, we may be able to find the following: 1. It is polymorphic, the gene group of A.B.C.D. DR locus is found along with many haplo-type. 2. Antigen differs accorbing to race. Example: HLA B8=White people 0.1% Oriental people 0.001% 3. It is related to disease. 4. There are few cases in the Department of Pediatrics but the result Shows A2, A9, B5 and B40 which is very similar to that of Japanese. There has been no Korean specific antigen founb yet.