OBJECTIVE: Prenteral nutrition therapy helps to increase the survival rate of preterm infants. However, due to their immature functions of liver, kidneys and lungs, and the poor capacity of lipid clearances and antioxidation, the dysfunction of hepatobiliary system induced by parenteral nutrition has drawn more attentions. Thus, this study was designed to investigate the effects of parenteral nutrition on the hepatobiliary function in preterm infants. METHODS: Seventy-five preterm infants who received partial parenteral nutrition from 1999 to 2004 were enrolled (Study group). Forty-nine preterm infants whose calories were provided only by glucose or glucose-containing electrolyte solutions were used as Control group. The two groups were matched in gender, gestational age, birth weight and Apgar scores at birth. The results of hepatobiliary function-related biochemical markers during parenteral nutritional administration were analyzed. RESULTS: After parenteral nutritional administration, the levels of serum glutamic oxaloacetic transaminase(AST), total bilirubin(TBIL), and indirect bilirubin(IBIL)in both groups decreased significantly(P<0.01), but the levels of serum glutamic pyruvic transaminase(ALT)and direct bilirubin(DBIL) remained unchanged. In the Study group, the level of serum total bile acid(TBA)increased significantly after parenteral nutritional administration (32.09±18.23 μmol/L vs 14.92±10.87 μmol/L , P<0.01). It was positively correlated to the duration of parenteral nutrition,and negatively to the gestational age. The TBA level of the Control group was not significantly different before and after nutritional administration. CONCLUSIONS: The TBA level significantly increased after parenteral nutrition administration, suggesting that parenteral nutrition-related cholestasis might developed in preterm infants.