Congenital biliary atresia (CBA) is a disorder of early infancy that needs early and accurate diagnosis because the curability may be increased if surgical therapy (hepatic porto-enterostomy) is performed early in the disease course of this condition. But immediate differentitation of CBA from neonatal hepatitis (NH) is very difficult and even special tests for differential diagnosis are of limited value because of some hazards, requirement of long time, technical difficulties and so on. The data of 14 patients with CBA and 20 with NH on admission at Tenri Hospital were analized by two statistical methods (discriminant analysis and probit analysis) then scores combining several simple variables were calculated. We tried to differentiate these two conditions by the scoring systems mentioned above, and checked the results of these methods against cases of other hospitals (CBA 6 cases and NH 15 cases). Our scoring systems presented here showed that they had higher discriminant power than any single variable including ^<131>I-BSP excretion test. They are available in the case that to cost any time for differential diagnosis is not allowed.