Abstract: This paper deals with the effect of different experimental conditions including the number of parasite, blocking fluid, incubation time and different types of antigens on dot ELISA for Trichomonas vaginalis. Five microlitres of freshly washed intact worms at a concentration of 7.7×10 5-3×10 8 cells/ml were added onto nitrocellulose membrane blocked with 1% BSA, 10% bovine serum or milk power (0.1%,0.25%,0.5%,5%). Dot ELISA using nitrocellulose membrane containing whole cell antigen 2.5×10 7 cells/ml, blocked by 0.5% defatted milk power at 37℃ for one hour before the incubation in McAb, incubated at 37℃ for one hour in McAb and SPA respectively was found to give more promising results. The whole cell antigen could be preserved for four months at 4℃ and -20℃ .