BACKGROUND Many diseases can cause obstructive jaundice and then lead to a series of pathologic disorders. Thus preoperative assessment of liver function is of utmost importance. Traditional assessment is to monitor related indicators of liver function, but it is invasive and needs to be performed repeatedly. Color Doppler flow imaging (CDFI) was used to monitor blood flow of the hepatic artery and portal vein, a non-invasive method which can be used repeatedly. METHODS Twenty cases of obstructive jaundice were detected by CDFI and changes of liver function were measured after operation. The variables of hemodynamic monitoring included peak flow rate and mean blood flow in the hepatic artery proper at the peak of the contraction period; the inner diameter of blood vessels, the peak flow rate, and the congestion index, the blood flow in the main portal vein. RESULTS The average peak flow rate in the hepatic artery of patients with obstructive jaundice was significantly higher than that of normal people; both the inner diameter and congestive index of the portal vein were significantly larger than those of normal people. But the mean blood flow and peak flow rate in the portal vein were lower than those of normal people. CONCLUSIONS CDFI is an ideal and non-invasive method for evaluating liver hemodynamics in obstructive jaundice. If the increase of hepatic arterial flow is more significant than the decrease of the blood flow in the portal vein, hepatic functional recovery after operation is smoother, suggesting a better prognosis. If the increase of the hepatic arterial flow is less significant than the decrease of the blood flow in the portal vein, hepatic functional recovery after operation may not be smooth, suggesting a worse prognosis.