The chemiluminescence reaction of amidopyrine-potassium permanganate with formaldehyde as an enhancer was investigated by flow injection system. A method for the determination of amidopyrine on the basis of this technique was proposed. The detection limit is 3.0×10-8 g/mL, the relative standard deviation is 1.3% (4.0×10-6 g/mL amidopyrine,n=11).The linear range is 1.0×10-7~8.0×10-5g/mL amidopyrine. The method has been applied to the determination of amidopyrine in the antondin injection.