Both immunoenzymatic staining technique (IEST) and indirect fluorescent antibody test. (IFAT) with frozen sections of adult Clonorchis sinensis as antigen were employed for detecting 51 cases with clonorchiasis and 50 healthy persons. The positive rate was 92% with IEST and 88% with IFAT. The results showed no significant statistic difference (P > 0.05). The false positive rates were 2% with the former and 4% with the latter. When sera from 22 cases with acute schistosomiasis, 20 cases with chronic schistosomiasis and 15 cases with paragonimiasis were examined by IEST and IFAT, cross-reactions were 14%, 5% and 0% with IEST, and 14%, 10% and 0% with IFAT, respectively. The results showed that both IEST and IFAT are useful methods for serological diagnosis of clonorchiasis and the antigen on the gut was well demonstrated, while IEST might be more suitable in field surveys.