Objective:To screen and obtain hybridoma cells secreting antibody of group A Neisseria meningitidis polysaccharide,produce monoclonal antibody,and establish an indirect compete ELISA based on McAb to detect A polysaccharide content in group ACYW135 meningococcal polysaccharide vaccine. Methods:Hybridoma cells were screened by hybridoma technology,McAb was produced by injecting cells into mice abdominal cavity,the indirect compete ELISA was developed through optimizing the test conditions,A polysaccharide content was detected in 5 groups of ACYW135 meningococcal polysaccharide vaccines from the same batch and 3 from different patches separately. Data were analyzed through one-samples T test in SPSS. Results:The equation of linear regression after Log-logit processing:y=-1.664 8-2.254 2x,R2 =0.989 5,the linear detection range was 0.022 8~1.200 7 μg/mL,IC50=0.165 8 μg/mL,and the lowest detection limit of this method was 0.022 8 μg/mL. A polysaccharide content was detected in the vaccines. There were no significant differences between detected value and original value(P > 0.05). Conclusion:We successfully screened the hybridoma cell and produced the McAb,provided indirect compete ELISA with good sensitivity,stability and repeatability,which detects A polysaccharide content in the process of meningococcal vaccine. It can overcome the difficulties that phosphorus content method and rocket eletroimmunoassay have.