This paper reports the preparation and identification of two monoclonal antibodies against FTB, and the establishment of an indirect competitive ELISA methods for FTB determination in buckwheat, rice, and corn. Two of the hybridoma cell lines (1C9 and 2D10), which could produce specific antibodies against fumitremorgin B(FTB), were selected and developed. The affinity Kaff constants of the monoclonal antibodies with the coating antigen, FTBS-IgG, were found to be 6 x 10(8) M-1 and 9.8 x 10 M-1, respectively. The isotypes of the monoclonal antibodies are of two isotypes, IgG1 and IgM, respectively. The antibody titers were found around 1 x 10(6) and 1.5 x 10(6). The standard curves showed that as little as 5 pg of FTB in 50 mL could be detected, and the linear range of standard curve was from 10 pg to 1000 pg of standard FTB. There were no cross-reaction for McAbs in the assay system with some mycotoxins tested. The mean recovery rate from buckwheat spiked with 10-60 ng/g of FTB was 78-88.7%.