OBJECTIVE: To study the material basis of the tonifying effect of Radix Changii by observing its contents of nutrient elements. METHODS: The contents of vitamins in Radix Changii and inorganic elements in the water extracts of it were tested by high performance liquid chromatography, fluorescence spectrophotography and scanning electron microanalysis. RESULTS: Radix Changii contains fat-soluble vitamins E and K 259.2 and 64.1 microg/kg respectively, and water-soluble vitamins C, B1 and B2 78.5, 0.6 and 0.7 mg/kg respectively. Its decoction contains abundant potassium and calcium ions. CONCLUSION: Radix Changii is rich in elements necessary for human body. It has the material basis for tonification.