A dominant VAT(variant antigen type) of Trypanosoma evansi was usued as solube antigen to establish an indirect ELISA for Trypanosoma evansi in water buffaloes. The results indicated that the established method had very high sensitivity,specitivity,and good effects were obtained by using this method to detect experimentally infected samples. This research set up a base for further establishing an indirect ELISA for Trypanosoma evansi in clinical use.