Abstract: The serum neutralizing antibody titer reflects the serum neutralization ability on virus infection. It is one of the important parameters for vaccine and virus infection evaluation. Liquid phase block ELISA is a method detecting antibody titer by the ELISA. So relationship between LPB-ELISA antibody titers and neutralizing antibody titer is valuable in vaccines and theoretical study. In this study, 90 bovine serum which were all collected from field were used to do LPB-ELISA test and neutralizing test. The results showed that there was correlation between the neutralizing antibody titer and the LPB-ELISA titers. The correlation coefficient was 0.642. But 41% tested antibody-negative samples detected by the LPB-ELISA was positive. By changing the criteria of LPB-ELISA positive，using suppression rate >0.7 calculation of antibody titer and 1/8 criteria, the LPB-ELISA results and the neutralizing antibody titer were in better coincidence, the false positive rate was reduced, so that LPB-ELISA was more suitable for foot and mouth disease serological monitoring and survey.

Key words: foot and mouth disease; liquid-phase blocking enzyme-linked immunosorbent assay; antibody titer