During 9 months (March-November, 1989), observation of Leucocytozoon infection rate to blood and parenchymatous viscera (spleen, liver, heart) in Pusan, Gyeongnam (Kimhae, Yangsan) districts slaughtered chicken and the results obtained were as follow : 1. Among the blood smear sample of 213 heads of the chicken, 43 heads (20.2%) were infected with Leucocytozoon 2nd stage gametocyte and 4 heads (1.9%) were mixed infected with Leucocytozoon 5th stage gametocyte. 2. In histopathological detection of schizont in tissues section of spleen, liver and heart, there were 16.7% in spleen, 5.6％ in liver and 9.1％ in heart, mean detection rate were 10.6%. Spleen had the highest detection rate of schizont. 3. In seasonal-related Infection rate, summer was higher than spring.