Abstract: Objective:To detect whether the serum of the rats irrigated with rhubarb and leech contain the main components of these two drugs, and to provide theoretical basis for clinical use of drugs.Methods:The effective components, rhein, emodin and hypoxanthine, in serum of rhubarb group and leech group were determined by HPLC.Results:The rat serum of rhubarb group contained rhein and emodin;although the detection of rhein had certain interference, emodin could be detected. Hypoxanthine could be detected in the rat serum of leech group.Conclusion:It is confirmed that the main chemical constituents of rhubarb and leech are found in rat serum.

Key words: High performance liquid chromatography, Rhein, Emodin, Hypoxanthine