Abstract: Fingerprinting provides a method to analyze the complex constituents in traditional Chinese prescriptions.Dachengqi decoction was,therefore,studied by HPLC fingerprint in order to offer the foundation for the study on the chemical material of this formula and the evidence for quality control of traditional Chinese drugs.Ten batches of Dachengqi decoction were measured by HPLC using Rhein as a reference substance and the chromatographic separation was performed on a Kromasil-C ₁₈column. A linear gradient elution with A (acetonitrile) and B (0.05%H₃PO₄) was used. The detection wavelength was set at 261 nm; the flow rate was 0.6 mL/min; and the column temperature was 30 ℃.Nineteen common peaks were signed,seven identified. Their similarity threshold was 0.97. The established method is accurate and repeatable,and can be used for the study on the chemical material of this formula and the evidence for quality control of traditional Chinese drugs.