Red blood cells of 40 wild mice captured at four different locations in the Ann Arbor area were typed for the presence of 15 different H-2 antigens by direct hemagglutination test. Fifteen different phenotypes were found and all were different from those determined by known H-2 alleles of the laboratory mice. Great similarity between phenotypes of mice from the sane location was observed. This is interpreted as further evidence for the deme structure of natural mouse population.