Abstract: Two hundred cases of Echinochasmus liliputanus infection were randomly divided into three groups and treated with pyquiton at a single dose of 10,5 and 2. 5 mg/kg, respectively. As assessed one month after treatment the egg negativity rates were 100%, 98. 7% and 96,5%, respectively. The symptoms such as abdominal pain, distension, diarrhea and anorexia relieved. The results suggest that pyquiton is effective against Echinochasmus liliputanus infection.