Objective To evaluate the impact of the inclusion of (MPSV-AC) vaccine in the Expanded Program on Immunization (EPI) on the incidence of meningococcal meningitis. Methods Data on the incidence of meningococcal meningitis in Liaoning from 1995 to 2019 were collected, Interrupted time series (ITS) analysis was used to assess the level and slope change of the incidence of meningococcal meningitis before and after the inclusion of MPSV-AC vaccine in the EPI. Results Before the MPSV-AC vaccine was included in the EPI, the average annual incidence rate of meningococcal meningitis was 0.3442/100 000, the incidence rate showed a descending trend with an annual decrement of 0.0319/100 000. After the MPSV-AC vaccine was included in the EPI, the average annual incidence rate of meningococcal meningitis was 0.0151/100 000 and he incidence of meningococcal meningitis showed a descending trend with an annual decrement of 0.0042/100 000. Conclusion The incidence of meningococcal meningitis reduced after the inclusion of MPSV-AC vaccine in EPI，and the EPI strategy had a continuous effect on the decreasing trend of meningococcal meningitis incidence.