To establish the determination method of dauricine (Dau) concentration in rats' blood and other biological samples, a reverse-phase HPLC method was adopted. Under the given condition, dauricine could be well separated. The retention time (tR) of Dau and its internal standard, daurisoline were 9.2 and 6.1 respectively. The detection limit was 10(-2) mg/ml. The absolute recoveries of all kinds of samples were above 70%, and the relative ones were over 85%. A good liner relationship has been obtained over the entire range of 0.030 to 3.000 mg/L in blood samples and 0.050 to 5.000 mg/L in other tissue samples. The intraday and interday coefficients of variation were below 10%. The results showed that the method can be used for detecting Dau in all kinds of biological samples.