Abstract： Objective To analyze the imaging characteristics of hepatic involvement in Langerhans cell histiocytosis(LCH) in children on MRCP, MRI and CT. Methods Twenty-nine children from three children hospitals in China, who were diagnosed as hepatic involvement by disseminated LCH during Aug 2008 and Jan 2015 were included in this study. Their MRCP (n=16), MRI (n=22), contrast?enhanced CT (n=15) data were retrospectively analyzed. The stenoses and dilatation of the intrahepatic bile ducts, the common hepatic bile duct and its first order branches and the common bile duct were evaluated on the MRCP image. The size and shape of the liver, the imaging characteristics of the periportal lesions in the Glisson sheath and hepatic parenchymal lesions were also evaluated on the cross?sectional images. Results MRCP indicated alternative stenoses/dilatation of the bile duct tree (n=16), stenoses of the common hepatic duct and its first?order branches (n=15), partialindistinctness of the common bile duct (n=2) and multiple cystic lesions along the biliary tree (n=5). On the cross?sectional images, the periportal lesions in the Glisson sheath were observed in 28 children. On MRI, the periportal lesions were shown in all the 22 children with MRI, presented as hypo-signal intensity on T1WI, hyper?signal intensity on T2WI (n=11) or mixed?signal intensity on T1WI and T2WI (n=11); On CT, the periportal lesions were found in 14 of the 15 children with CT, presenting as low density (n=13) and mixed density (n=1). Multiple nodular or cyst?like parenchymal lesions were observed in 21 patients including 18 patients on MRI and 5 patients on enhanced CT. Sixteen patients presented as hypo?intensity on T1WI, hyper?intensity on T2WI and low density on plain CT, and 5 patients with iso? or hypo?intensity on T1WI, hypo?intensity on T2WI,and milder enhancement relative to the adjacent parenchyma on contrast?enhanced CT. Conclusions The imaging characteristics of hepatic involvement by LCH include alternative stenoses and dilatation of the intrahepatic ducts, stenoses of the common hepatic bile duct and its first?order branches on MRCP, the periportal lesions in the Glisson sheath and hepatic parenchymal nodular or cyst?like lesions on cross?sectional images.