Objective To analyze the occurrence characteristics of AEFI and the operation of AEFI monitoring system in Yunfu City from 2015 to 2019. Methods The case data of Yunfu City from 2015 to 2019 were collected through the national AEFI information management system,and the occurrence of AEFI was analyzed by descriptive epidemiological method. Results A total of 578 cases of AEFI were reported in Yunfu City from 2015 to 2019(the reported incidence was 8.69/100000 doses).A total of 281 cases (48.62%) mainly occurred from May to August,and 217 cases (37.54%) mainly occurred in 0-year-old group. 90.83% of AEFI cases occurred within 24 hours after vaccination. Except that the reporting rate within 48 hours in 2015,the timely reporting rate of questionnaire and the reporting rate within 48 hours in 2016 were not up to the standard,all indicators in other years met the requirements of the national AEFI monitoring program.There were 359 general reactions (62.11%) and 192 abnormal reactions (33.22%).The vaccines involved in the number of reported cases were mainly acellular DPT combined vaccine (DTaP),measles rubella combined live attenuated vaccine (MR) and Japanese encephalitis live attenuated vaccine (jev-l).99.48% of the cases had good prognosis. Conclusion The monitoring of AEFI in Yunfu City works well and the safety of vaccination is good.