Abstract: After the root, stem, flower and leaf of Sedum aizoon L. were crushed, the soxhlet extraction was carried out with methanol as solvent. Then, the content of total flavonoids in different organs was determined by the developed ultraviolet spectrophotometry method at the optimal maximum absorption wavelength of 365 nm with rutin as reference substance and NaNO₂-A1（NO₃）₃-NaOH as chromogenic agent. A good linear behaviors over the investigated concentration ranges of 8~40 μg/g were observed with the regression equation of y=0.017 5x+0.04（R²=0.999 9） for the test. The recoveries of added rutin at low, medium and high concentration levels in different organs was 92%~94%, RSD≤5%. The contents of total flavonoids in roots, stems, flower s and leaves of Sedum aizoon L. were （29.44±1.37）, （27.96±0.87）, （9.79±0.36） and （16.16±0.50） mg/g, respectively. This study established a simple and accurate method for the determination of total flavonoids in different organs of Sedum aizoon L., which provided a scientific basis for the detection and targeted development and utilization of the flavonoids in Sedum aizoon L.

Key words: Sedum aizoon L., total flavonoids, different organs, content determination, UV spectrophotometry