Abstract: Objective To analyze the adverse events following immunization (AEFI) in Shijingshan district of Beijing in 2012 and evaluate the performance of AEFI surveillance system. Methods Descriptive epidemiological analysis was conducted on the incidence data of AEFI in Beijing during this period. Result A total of 45 AEFI were reported, the incidence rate was 17.02/lakh, Fourteen kinds of vaccines were involved. The cases number caused by diphtheria-tetanus-acellular-pertussis vaccine (DTaP) were highest (13, 28.89%), while the incidence of cases caused by pneumococcal conjugate vaccine against 7 pneumococcal serotypes (PCV7) was highest (116.91/lakh). In the classification of AEFI cases, 53.33% were general reactions, 28.89% were abnormal reactions and 17.78% were coincidental cases. Up to 75.56% of the cases were children aged 2 years, the cases mainly occurred between May-October and 95.56% of the cases occurred within 1 day after vaccination. Conclusion The sensitivity and completeness of AEFI surveillance in Shijingshan were well, but still needed improvement. To reduce the AEFI, it is necessary to conduct standard vaccination and distinguish contraindications.