Objective To investigate the correlation between the plasma endothelin (ET) and gastric mucosal pathology.MethodsIn this experiment,seven dogs who experienced common bileduct ligation were in experiment group, the other three dogs who underwent shamoperation were control group. By using specific radio immunological method, the plasma ET levels were determined in dogs before and after 1,4,7 d. The total bilirubin levels were determined before and after 1,4,7 d after operation by using carbazotic acid method.The gastric mucosa,7 d after operation, was cut into slices and was examined under the electron microscope and the light microscope.Results In the experiment group,the levels of ET and total bilirubin rose continually and were higher than those in control group. Vascular congestion and oedema were seen in gastric mucosa of common bileduct ligated dogs. Under the electron microscope, we could see the dilated blood capillary and sludging of blood,the intenstitial mucusa cells oedema. Conclusion The increase of plasma ET might lead to impairment of mucosal microcirculation,which might be one of the pathogens that could induce the gastric mucosal damages in common bileduct ligated dogs.