To establish immortalized human B-cells secreting antibodies to cedar pollen allergens, peripheral blood lymphocytes from 13 donors were transformed with Epstein-Barr virus. Of 5000 micro culture wells with transformed cell growth, supernatants from 88 wells were found to contain antibodies to pollen allergens. Fourteen supernatants reacted with a cedar allergen Cry j1 and 10 reacted with Cry j2. IgM class antibodies were predominant.