On the basis of inhibition of chemiluminescence reaction of luminol and potassium permanganate in sodium hydroxide medium by 3-nitropropionic acid, a novel flow-injection chemiluminescence method for determination of 3-nitropropionic acid in drinking water was developed. A linear range for 3-nitropropionic acid determination was 1～150 mg/L. The detection limit of 3-nitropropionic acid was 0.28 mg/L and relative standard deviation (RSD) was 1.9%, with the recovery of 76.5%～93.8%. This online determination system showed a good accuracy and selectivity and has great potential application in rapid detection and alarm of emergency pollution of 3-nitropropionic acid in drinking water.