Abstract: A simple quantitative method of BrO₃^－ and Br^－ in flour using high performance liquid chromatography -inductively coupled plasma mass spectrometry was established. The detection limits for BrO₃^－ and Br^－(counted as Br) were 0.052 µg•L^－1 and 0.048 µg•L^－1, respectively. Three sample preparation methods were compared including ultrasonic method, bathing method and oscillation method. Oscillation method was selected finally. The recoveries of BrO₃^－ and Br^－ are between 93% and 112%.