An HPLC method was developed for the simultaneous determination of 11 constituents, 5-hydroxymethyl furfural (5-HMF), vicenin-2, hesperidin, hesperetin, isosinensetin, sinensetin, tetramethyl-O-isoscutellarein (TEOS), nobiletin, 3,5,6,7,8,3',4'-heptamethoxyflavone (HEPTA), tangeretin, 5-demethylnobiletin in Citrus reticulate 'Chachi'. The separation was conducted on a Hanbon Benatach C18 column (250 mm×4.6 mm, 5 μm) with acetonitrile and 0.2% formic acid as mobile phases with gradient elution. The flow rate was 1.0 mL/min. The detection wavelength was 280 nm. The column temperature was 25 ℃. The results showed that the correlation coefficients (r) between concentration and chromatographic peak area of the 11 constituents were over 0.998 in the selected linear ranges. The limits of detection (LODs, S/N=3) and limits of quantification (LOQs, S/N=10) of the 11 constituents were in the range of 0.0125-1.25 mg/L and 0.0502-4.99 mg/L, respectively. The average recoveries (n=3) of the 11 constituents were in the range of 96.4%-102.4% and the RSDs were 0.25%-4.01%. The developed method has been successfully applied for the analysis of eight samples from different cultivation regions in Guangdong Province. This method is simple, accurate and effective for the simultaneous determination of the 11 components, and suitable for the quality control of Citrus reticulate 'Chachi'.