OBJECTIVE：To establish the quality standard of Corydalis tomentella. METHODS： The medicinal material was identified in respects of property， microscopic characteristics and TLC. The contents of moisture， total ash and water soluble extract were determined. The content of dehydrocavidine was determined by HPLC. The determination was performed on Agilent C18 column with mobile phase consisted of acetonitrile-phosphate buffer solution （containing 20 mmol/L monopotassium phosphate， 10 mmol/L diethylamine， 0.1％phosphoric acid）（28 ∶ 72，V/V） at the flow rate of 1.0 mL/min. The detection wavelength was set at 347 nm， and the column temperature was 35 ℃. The sample size was 10 μL. RESULTS： The original plant is perennial herbs. The medicinal material often shrank into a ball. The main root was in conical shape； the rhizomes and roots were distinctly chapped； leaves curled and broken， and flowers were yellowish-white. The pollen grains were round-like in shape； square and columnar crystals were found； there were a large number of nonglandular hairs. The bordered pit， threaded and reticulate catheter were found； wood fiber was also found. TLC spots were clear and well-separated. The content of moisture were 7.5％-18.5％， total ash were 20.5％-26.2％，and extract were 29.9％-46.4％. The linear range of dehydrocavidine were 0.040 08-2.404 8 μg （r＝0.999 9）； RSDs of precision， stability and reproducibility tests were lower than 2.0％. The recoveries were 95.6％-102.5％（RSD＝2.3％，n＝9）. CONCLUSIONS： The established standard can be used for quality evaluation of C. tomentella.