OBJECTIVE： To establish the HPLC fingerprints for Sini decoction and compare the differences of compositions of Sini decoction prepared by traditional decoction and modern machine decoction. METHODS： HPLC was performed on the column of Kromasil C18 with mobile phase of acetonitrile -0.1％ phosphoric acid （gradient elution） at a flow rate of 1.0 ml/min， the detection wavelength was 235 nm， column temperature was 30 ℃， and injection volume was 10 μl. The HPLC fingerprints of 10 batches of Sini decoction were determined with reference peak of liquiritin peaks， and common peak identification and similarity evaluation were conducted by using Chromatographic Fingerprint Similarity Evaluation System （2004 A edition）. RESULTS： There were 18 common peaks and the similarity was no less than 0.982. According to the verification， the fingerprint of 10 batches of Sini decoction showed good similarity with reference fingerprint， and the similarity of 10 batches of Sini decoction was high， which was prepared by the 2 methods. CONCLUSIONS： The established fingerprint is specific and stable， and can provide reference for quality evaluation and control for Sini decoction； and there are no obvious differences in the main chemical compositions of Sini decoction prepared by traditional decoction and modern machine decoction.