Abstract: Objective To discuss the clinical features, hepatic ultrastructure, and prognosis of 3β-hydroxy-Δ5-C27 steroid dehydrogenase deficiency caused by mutation of HSD3B7 in children. Methods Clinical features of 3β-hydroxy-Δ5-C27 steroid dehydrogenase deficiency in two children from one family were analyzed retrospectively. The related literatures were also reviewed. Results Two children in one family had different degrees of cholestasis, hepatomegaly, growth retardation, and renal cyst. The serum transaminases was elevated, and the γ-glutamyl GGT (γ-GT) and total bile acid were normal. The hepatic pathology showed intrahepatic cholestasis, inflammatory cell infiltration, hyperplasia of smooth endoplasmic reticulum, increase of glycogenosome, and expansion and hyperplasia of bile capillary. Gene testing found homozygous mutation of HSD3B7 (c.130_131insA) in both children. Conclusions It should be alerted to the possibility of the bile acid synthesis disorder, when infants have cholestasis, elevated transaminase, hepatomegaly, and normal or reduced γ-GT and total bile acid. Gene testing should be completed as soon as possible for early diagnose and therapy.