[Objective] To establish a method for determining the content of total flavonoids in Mukdenia rossii (Oliv.) Koidz.[Method] By comparison of two color development methods,AlCl3 was chosen as the color-developing agent.With the detection wavelength at 270 nm,the ultraviolet-visible spectrophotometry was adopted to determine the content of total flavonoids in M.rossii.[Result] The mass concentration of total flavonoids in M.rossii was linearly related to absorbance in the range of 0 to 0.024 mg/ml with the correlation coefficient of 0.999 8.The content of total flavonoids in M.rossii was 11.099 mg/g.[Conclusion] The ultraviolet-visible spectrophotometry is a simple and fast method with high precision,reproducibility and stability that is fitter to determine the content of total flavonoids in M.rossii. [Objective] To establish a method for determining the content of total flavonoids in Mukdenia rossii (Oliv.) Koidz. [Method] By comparison of two color development methods, AlCl3 was chosen as the color-developing agent. nm, the ultraviolet-visible spectrophotometry was adopted to determine the content of total flavonoids in M.rossii. [Result] The mass concentration of total flavonoids in M.rossii was linearly related to absorbance in the range of 0 to 0.024 mg / ml with the correlation coefficient of 0.999 8. The content of total flavonoids in M. crossii was 11.099 mg / g. [Conclusion] The ultraviolet-visible spectrophotometry is a simple and fast method with high precision, reproducibility and stability that is fitter to determine the content of total flavonoids in M.rossii.