OBJECTIVE To determine the contents of monotropein in the different processed Products of Radix Morindae. METHODS CONCLUSIONS Kromasil C18 (150 mm x 4. 6 mm,5 micorm) column; The mobile phase was methol-0.4% phosphate solution (5:95-->28.8: 71.2, 15 min); The velocity of flow was 1 ml/min; The detection wavelength was at 210 nm; And column temperature was 25 degrees C RESULTS: There were obvious differences between the crude and kinds of different processed products of monotropein in the Radix Morindae, The contents of monotropein from the different processed products (crude drugs, removed from wood, processed with salt, prepared) were 13.92 mg/g,9.10 mg/g, 9.21 mg/g, 12.86 mg/g, respectively. CONCLUSIONS The different processing methods can make the contents of monotropein in the Radix Morindae.