Abstract: In order to compare the methods for determing the antibody against Neisseria meningitidis (Nm) Serogroup A,the sera samples collected from 129 healthy population in Gannan county were detected by using ELISA.When capsular polysaccharide (CPS) or strain of Nm serogroup A was used as a coating antigen in ELISA,the positive rates of antibody against Nm serogroup A were 80.6% and 69.0%,and their geometric mean titers (GMTs) were 1∶6.38 and 1∶5.46,respectively.In addition,46 samples of sera with enough quantity were detected by using bactericidal test and ELISA at the same time.The positive rate of bactercidal antibody to Nm serogroup A was 67.4% and its GMT was 1:9.16.When the above CPS or strain was used as a coating antigen in ELISA,the positive rates of the above antibody were 73.9% and 71.7%,and their GMTs were 1:7.53 and 1:7.20,respectively.It indicated that the positive rates and GMTs of the above antibody detected by ELISA were similar to the positive rate and GMT of bactericidal test,but CPS of Nm serogroup A was better than the strain of Nm serogroup A when were used as coating antigens in the ELISA test.