In order to assess the reliability of ultrasonographic criteria of clonorchiasis, a prospective study was performed in 14 patients who were diagnosed as clonorchiasis by ultrasonogram only, using the criteria of peripheral duct dilatation without dilatation of extrah epatic duct. Eleven out of 14 patients were turned out to be clonorchiasis, showing 93% accuracy. Authors in tend to stress these ultrasonographic signs are very well correlated with the CT and E RCP findings and are proved to be highly reliable for clonorchiasis, and thus clonorchiasis could be diagnosed by ultrasonogram only.