Objective:To determine obstruction property according to degree and morphology of bile tract dilation.Methods:76 cases with bile tract dilation were analyzed.Degree and morphology of intra-hepatic bile tract dilatation

change of end of extra-hepatic bile tract dilatation

obstruction

gallbladder expansion and pancreatic duct dilation were observed and registered.Results:The symptoms of malignant intra-hepatic bile tract dilatation were as following:moderate and severe dilation

most of soft ratten-like bile tracts and a sudden cut in proximal coverage;while the symptoms of optimum intra-hepatic bile tract dilatation were as follows:slight dilation

most of withered bile tracts and a gradual thinning in distal coverage.Conclusion:obstruction property can be determined by degree and morphology of intra-hepatic bile tract dilation

change of end of extra-hepatic bile tract dilation

and obstruction location.