Abstract: Twenty-nine cases of acute lymphocytic leukemia in children were obsevated by us. In four of them the leukemia was complicated by hepatitis B and 25 cases were not. The mean survival period in the hepatitic group was 73.0±13.0 months whereas that in the non-hepatitic group was 23.4±2.6 months （X~2=6.680,P＜0.01）. Up to Mar. 1985, 3 cases of hepatitic group were still alive. It appears that hepatitis B may influence the clinical course of acute leukemia in children.