Abstract: Using purified rabbit polyclonal antibodies to SEA,avidin biotin system and capture ELISA technique,we observed the dynamic changes in the level of the circulating soluble egg antigen antibody complex(SEAIC)in murine sera at various weeks post infection.Simultaneously,the diameter and area of liver egg granuloma were measured by using profile analytical technique.Serum SEAIC was first detected 4 weeks post infection(p.i.),reaching peak level at 6-7th week,and then gradually dropped,and maintained at moderately high level till the end of the observation(12 weeks p.i. ).Schistosome eggs appeared in liver tissue at 4 weeks p.i..No egg granuloma could be found until 6 weeks p.i..The peak of the average diameter and area of liver egg granuloma was noted at 7 weeks p.i.,then dropped gradually.Its dynamic changes were consistent with that of the serum SEAIC level.It is therefore suggested that the serum SEAIC level could be a reference index reflecting the extent of the pathological changes of the liver.Moreover,SEAIC might play an important role in the pathogenesis of schistosomiasis japonica.