Objective:To analyze the results of application on automated-alert and response system of infectious diseases in Jiangsu province from 2009 to 2011,and to provide scientific evidence for the improvement of the system. Methods:Descriptive study is applied to analysis the outcome of signal,classification of diseases,response time to signal,and manner of signal verification,using the data of the infectious diseases automated-alert and response system from 2009 to 2011. Results:A total of 31 649 early-warning signals were detected from 2009 to 2011,with signal response rate of 99.93% and positive rate of 0.6%. There was a positive correlation between the number of signals and the notifiable disease in municipalities. The season distribution of signals had two peaks at spring-summer and fall-semester. The response rates were on rise year by year,with 99.79%,99.99% and 100.00% respectively. Comprehensive analysis,accounting for 54.02% in all methods of signal verification,was the primary method to verify the early-warning of a single case,and the median response time was 0.23 h to 0.33 h. Surveillance data analysis was accounting for 47.57%,for early-warning signal by the time model method,and the median response time was 0.49 h to 0.76 h. Conclusion:The infectious diseases automated-alert and response system was stable and effective. This system had an important role in the early discover of priority case and prediction of disease pandemics. However,to optimize the early warning system,better parameters of early-warning and source of data should be need.