OBJECTIVE： To establish a method for simultaneous determination of 4 effective components in the couple of Coptidis Rhizoma and Evodiae Fructus，and to investigate rational proportion of the couple. METHODS： HPLC method was adopted. The determination was performed on Welch XB C18 column with mobile phase consisted of acetonitrile-1.5 mmol/L sodium dodecyl sulfate solution （pH adjusted to 5.0 with phosphoric acid） （gradient elution） at the flow rate of 1.0 mL/min. The detection wavelength was set at 265 nm， and the column temperature was 30 ℃. The sample size was 10 μL. RESULTS： The linear ranges of berberine hydrochloride， martin hydrochloride， evodiamine and rutacarpine were 2.24-44.80 μg/mL（r＝0.999 9）， 1.26-31.50 μg/mL（r＝0.999 8）， 2.70-81.00 μg/mL（r＝0.999 8）， 1.65-49.50 μg mL（r＝0.999 9）， respectively. RSDs of precision， stability and reproducibility tests were all lower than 3.0％. The recoveries were 98.11％-100.73％（RSD＝1.04％，n＝6），96.54％-103.47％（RSD＝1.86％，n＝6）， 95.49％-102.36％（RSD＝2.05％，n＝6）， 97.19％-103.24％（RSD＝2.19％，n＝6）， respectively. When the proportion of Coptidis Rhizoma-Evodiae Fructus（m/m） was 2 ∶ 1， the comprehensive content of each component was the highest. CONCLUSIONS： The method is simple， accurate， stable and reproducible， and can be used for simultaneous determination of 4 effective components in different compatibility proportions of the couple of Coptidis Rhizoma and Evodiae Fructus. The rational proportion of the couple of Coptidis Rhizoma and Evodiae Fructus is 2 ∶ 1.