Lomatogonium rotatum (L.) Fries, Gentianopsis barbata (Froel) Ma, and Gentianella acuta (Michx.) Hulten, the three kinds of Digeda-species Mongolian medicinal materials belonging to the family Gentianaceae, bad been widely used for the treatment of liver diseases. To analyze comparatively the content of swertiamarin and swertisin among these three kinds of Digeda-species Mongolian medicinal materials. HPLC method was applied for qualitative and quantitative analysis of swertiamarin and swertisin. The Phenomenex C18 (4.6 mm x 250 mm, 5 μm) was used, chromatographic methanol and water as mobile phase, the flow rate was 1.5 mL x min(-1) with UV detected at 237 nm, column oven temperature was 25 degrees C. Results showed that the contents of swertiamarin and swertisin were closely related the different species and producing areas. The content range of swertiamarin in L. rotatum from different habitats was 1.73% - 2.72%, 0.43% - 0.96% for the swertisin content; the content of swertiamarin in G. barbata from Alxa Left Banner was 0.38%, and the content of swertiamarin and swertisin in G. barbata from the others habitats and G. Acuta from different habitats were all detected qualitatively. The contents of swertiamarin and swertisin among these medicinal plants showed a significant difference due to the different species and producing areas. As a consequence, these medicinal plants should not be put together for clinical applications.