To develop a high performance liquid chromatography method for the determination of maleic acid and fumaric acid in flour products.Methods The flour product samples were extracted with 50 ml of 10% methanol and water, then centrifuged and filtered with 0.45 μm membrane. Waters Atlantis T3 chromatographic column was used to separate the sample with 0.1% phosphoric acid and methyl alcohol (95∶5, V/V) as the mobile phase. The samples were detected by UV-detector, the column temperature was 30 ℃ and the wavelength was 210 nm. Results Under the optimized experimental conditions, the calibration curve showed good linearity in the range of 0.1-25 μg/ml. The regression equation is y=147008x-1316.8 (r=0.999 5, n=6) for maleic acid, y=176689x-670.1 (r=0.999 6, n=6) for fumaric acid. The detection limit was 2.0 mg/kg with the recovery rate in the range of 86.88%-93.02%, and the relative standard deviation of method was 0.67%-1.08%.Conclusion The method was simple, accurate, and could be applied to the determination of maleic acid and fumaric acid in flour products.