Abstract: Carthamus tinctorius L. is a kind of traditional Chinese medicine used in the treatment of uterine congestion, cardio-vascular disease, thrombosis and so on. Eight flavonoids have been isolated from its flowers. A reversed phase HPLC method for the separation and determination of the three flavonols: rutin(I) , quercetin(II) and kaempferol(III) in the flowers of Carthamus tinctorius L. is described. The column was 25 cm×4.6 mm ID, packed with YWG-C₁₈ (10 μm). The mobile phase was a mixture of MeOH-H₂O-H₃PO₄(48.5∶51.5∶0.25, pH 3.5). The flow rate was 1.0 ml·min^-1. Daidzein was used as an internal standard. UV detection was performed at 360 nm. The relative standard deviation of the method was 1.1～2.6%. The calibration curves showed good linearity over the range of 0.11～0.80 μg,γ=0.9995～0.9998 and detection limits were 2.0～20.0 ng. The recoveries were 97.8%～98.9% for the three flavonols. The method is simple, fast, sensitive and accurate and has been applied to the analysis of Carthamus tinctorius L. of different sources. It can also be used for the quality control of safflower preparations for clinical uses.