Abstract: A rapid spectrophotometric method based on FIA for the content uniformity test of atropine sulfate tablets has been developed. By means of the self-designed FIA system with an on-line extraction device, many difficulties resulting from extraction, such as slow analytical rate, environmental pollution, poor reproducibility, etc, were overcome, and the routine procedure of the official content uniformity test was tremendously simplified. Results obtained with the proposed method agree well with those obtained with the official test. Furthermore, the proposed method attained a sampling rate of 60 samples per hour, a recovery of 100.0%, a relative standard deviation of 0.7%, and a detection limit of 0.24μg/ml. Uniform design proves effective to optimize complex FIA conditions, and FIA promises a new approach to test the content uniformity of pharmaceutical tablets.