The diagnosis of congenital biliary atresia can be confirmed by a series of tests, including dynamic examination of total serum bilirubin, general characterization of duodenal drainage, ultrasonography, nuclear scan, and ERCP and MRCP. The dynamic observation of bilirubin is performed by weekly measurement of serum bilirubin. If the curve of serum bilirubin amount, which is mainly elevated by direct bilirubin, continues to rise, it is ineffective to biliary medication; if it does not respond to phenobarbital and hormone treatment, it suggests biliary atresia. General characterization of the duodenal drainage was able to diagnose partial biliary obstruction due to structural abnormalities. In the early stage of biliary atresia hepatocytes functioned well and showed liver shadowing for five minutes, but no biliary shadowing was seen afterwards, which could be diagnosed as congenital biliary atresia. Ultrasonography shows dysplasia or absence of extrahepatic bile ducts and gallbladder. 99mTc-EHIDA scan of the intestine shows no nuclei. ERCP examination can detect congenital biliary atresia, for example, only pancreatic ducts can be visualized, and sometimes abnormalities of pancreaticobiliary cohesion can be detected. The MRCP is a non-invasive biliary imaging method that can perform biliary water imaging reconstruction and staging of atresia to guide further treatment.