Abstract: Sera of patients with bancroftian microfilaraemia were detected for antibodies using three different stage antigens of Brugia malayi, which were microfilaria treated with pa-pain (MTP), cryosection of infective larvae (CIL) and cryosection of adult worm (CAW) by indirect fluorescent antibody test.The experimental results showed that there were no statistical differences between MTP and CAW in sensitivity and specificity, the positive rate in patients with microfilaraemia being 95.3% and 93.7%, the false positive rate in pregnant women and infants in non-endemic area of filariasis being 3.9% and 0, and the cross-reaction rate in patients with cysticercosis being 12.5% and 25.0% respectively. The positive rate of CIL was 76.2%, the false positive rate was 11.5%, and cross-reaction rate was 18.8%.It is considered that the antigen of microfiiaria treated with papain might be more appropriate to be applied than the antigen of cryosection of adult worm in seroepidemio-logical investigation for bancroftian filariasis, due to the convenience and simplicity in the collection and preparation of antigen.