Objective To explore the clinical and genetic characteristics of progressive familial intrahepatic cholestasis (PFIC). Method Clinical data and genetic results of the patients were retrospectively analyzed. Peripheral blood samples were collected, and genomic DNA was extracted, whole exome sequencing (WES) was used to identify the genetic cause. Results Case 1, a 15 years old female, presented with jaundice, skin itching, white sticky stools, accompanied by splenomegaly; case 2 , a 3 years and 6 months old male, manifested as jaundice and skin itching. WES analysis revealed compound heterozygous mutations of c.2652 G>C from the father and c.1573 C>T from the mother in the ATP 8 B 1 gene of patient 1 . c.2652 G>C is a novel mutation which has not been reported before. In case 2 , WES identified a homozygous missense mutation of c.2606 A>C in the ABCB 11 gene, which were inherited from his parents. Conclusion The diagnosis of progressive familial intrahepatic cholestasis needs to combine clinical manifestations, histopathological findings and genetic testing, and to exclude other related diseases that lead to cholestasis; genetic testing is helpful for confirming the diagnosis and treatment of PFIC. The mutations reported in this paper enriched the pathogenic mutation spectrum of ATP 8 B 1.