Objective:To investigate the changes of cholesterol 7alpha-hydroxylase(CYP7A1),farnesoid X receptor（FXR）,and small heterodimer partner (SHP) expression in liver tissues of bile duct ligated (BDL) rats,and to analyze the relationship between their expression.Methods: Obstructive cholestasis rat model was induced by bile duct ligation,and rats were sacrificed on day 1,3,and 14 after operation.The hepatic tissues were collected and the total mRNA was extracted.The CYP7A1 mRNA expression was determined by real-time RT-PCR.The protein expression of FXR and SHP in the nuclei was determined by Western blotting analysis.Results: Compared with sham-operated group,experimental obstructive cholestasis group had significantly enhanced CYP7A1 mRNA expression and decreased FXR,SHP expression(P<0.001,P<0.05).Conclusion: The up-regulation of CYP7A1 may be associated with the down-regulation of FXR and SHP.