Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; The influences of age on hematological and serum biochemical parameters were investigated in juvenile ring-necked pheasant. Statistical comparisons were made for differences in values among different ages. A variety of blood parameters showed significantly age related differences. Juvenile ring-necked pheasants of all ages had lymphocytes as the major circulating leukocyte. RBC values for 60 day-old pheasants were lower than the values for 74, 88 and 102 day-old pheasants. The hemoglobin value was higher for 88 day-old pheasants. The WBC, the heterophil and the lymphocyte values were significantly higher for 60 day-old pheasants. Total serum protein, albumin and globulin values for 25 and 60 day-old pheasants were significantly lower than the values for 42, 88 and 102 day-old pheasants. © Asian Network for Scientific Information, 2007.