Abstract: Objective To evaluate the performance of China Infectious Disease Automated-alert and Response System (CIDARS) in China, and provide evidence for the improvement of the system. Methods The data of the automated alerts generated by the system, the responses to the alerts and alert confirmation were collected from 31 provinces in China in 2014. The analysis results were compared with the performance of the system during 2011-2013. Results A total of 386 578 alerts were generated nationwide on 33 infectious diseases, in which 383 637 (99.24%) were responded, and the median (P25-P75) of time for response was 1.0 (0.4-3.8)h. The overall response rate and the response rate in 24 hours in 2014 were higher than those during 2011-2013. Among all the alerts, 163 649 were generated by fixed-value detection method, in which 162 361 had responses (99.21%), and the median (P25-P75) of time for response was 1.0 (0.2-5.3)h. After the preliminary data verification, field investigation, and laboratory test, 80 923 alerts of disease cases were confirmed, accounting for 49.50% of the total alerts. In addition, 222 929 alerts were generated by the temporal aberration detection methods with an average 1.48 alerts per county in a week, and 3159 suspected outbreaks were confirmed, accounting for 1.42% of the total alerts. The response rate was 99.26%, and the median (P25-P75) of time for response was 1.1 (0.5-2.9)h. Conclusion In 2014, the response rate of alerts generated by CIDARS and its timeliness remained at a high level. The overall alert response rate and the response rate within 24 hours were improved compared with those during 2011-2013, but the confirmation of the alerts for suspected outbreaks needs further improvement.