This study aims to develop and test the method of control bar matrix for outbreak detection in a syndromic surveillance system (ISSC) of rural China. From the ISSC database, we extracted the historical daily number of outpatients with fever symptom reported in a township hospital surveillance unit from August 1st to December 31st as baseline data. Six different control bar algorithms (the matrix) were simultaneously run among baseline data to simulate the real-time detection. Findings showed that control bar matrix could label the alarms into hierarchical warning levels, which facilitated the signal verification and decision making in syndromic surveillance system.