Abstract: A facile and sensitive method for determination of isoprenaline was developed by flow injection coupled with chemiluminescence detection based on significant signal enhancement of isoprenaline on luminol-KIO₄ system. Parameters affecting both chemiluminescence intensity and reproducibility were optimized. Under the optimum conditions, the method psseses linear range from .0×10^-9 ~1.5×10^-6 mol/L with detection limit of 5.8×10^-10mol/L. The relative standard deviation was found to be 1.7% for 12 replicate determinations of 5.0×10^-7 mol/L isoprenaline. The analyzing throughput of the proposed method is about 130 samples/h. The application of the present method was demonstrated by analyzing isoprenaline in isoprenaline hydrochloride injection with the recoveries of 99.2%~103.2%. The possible mechanism of the enhanced chemiluminescence intensity was discussed by chemiluminescence spectra and UV-vis spectra