Abstract: A method was proposed for the determination of metaraminol bitartrate by flow injection chemiluminescence, based on that the chemiluminescence arising from the reaction of luminol with potassium permanganate could be strongly enhanced by metaraminol bitartrate in alkaline solution. The linearity range of metaraminol bitartrate was 0.01-10.0 mg·L-1, with detection limit of 3.7 μg·L-1. The method was applied to analyze metaraminol bitartrate injection, giving measured values in agreement with the indicated values and RSD (n=6) in the range of 1.5%-2.3%. The mechanism of chemiluminescence system was also explored by analyzing the fluorescence spectra of the system.