A simple, sensitive and accurate HPLC-DAD method was developed for simultaneous determination of evodiamine and rutaecarpine in Evodia rutaecarpa that has been widely used as one of the traditional Vietnamese medicines. The method was carried out by using a Gemini RP C18 column with a gradient solvent system of acetonitrile - methanol - water and a PDA detector (225 nm). The result found that contents of the alkaloids in Evodiae fructus extract could easily be determined within 30 minutes. All calibration curves showed good linear regression (r2>0.9999) within the concentration ranges of 2 - 100μg/ml for evodiamine and rutaecarpine. The RSDs of intra-day and inter-day were 3.54-4.74% and 1.89- 3.72% for evodiamine and rutaecarpine, respectively. The LOD were 0.0625 and 0.500 μg/ml, and the LOQ were 0.125 and 1.665 μg/ml, for evodiamine and rutaecarpine, respectively. The recovery was 99.8% for evodiamine and 96.4% for rutaecarpine. The validated method was successfully applied for the simultaneous determination of the two chemical constituents in 40 batches of samples collected from different regions in the market. The quantification data of them in Evodiae fructus were 0.017–1.522 g/100g for evodiamine and 0.050 – 1.470 g/100g for rutaecarpine. Hence, the validation procedure confirmed that this technique afforded reliable analysis of these components in complex matrices such as Evodiae fructus extracts. The method proposed was demonstrated to be very useful in guiding chosen herb use due to the relation of fruit maturity degree.