To detect the contamination level of fumonisin B1 in grain, and to develop rapid detection kit that possess patent of China.Hybridoma cell line excreting monoclonal antibody against fumonisin B, was produced using B cell hybridoma technique and develop a rapid, sensitive, quantitative ELISA-kit for detection fumonisin B1.The monoclonal antibody used in the ELISA-kit were tested for subtype as IgG1 and its affinity constant was 8.3 x 10(-8) mol/L. The monoclonal antibody obtained in the present study was highly specific to fumonisin B1 , because no cross reactions between the monoclonal antibodies against fumonisin B1 with the analogues of fumonisin B, were found. The limited concentration of the ELISA-kit was 5 ng/ml, linear range was 50-500 ng/ml, the linear equation was Y = -0.582 x +1.793( = 0.99, P < 0.05). The recovery rate of maize on the level of 50n g/ml, 200 ng/ml and 500 ng/ml was among 71.89%-112.95%. The kit can be stored at normal tempertature in ten months at least. The coefficient of variant winthin-laboratory and between-laboratory was less than 20%.