Abstract: OBJECTIVE To establish HPLC fingerprint of persicae semen before and after processing, and compare the quality difference of persicae semen before and after processing, and the difference between persicae semen and seed coat. METHODS HPLC was adopted to construct each of 10 batches the fingerprint of persicae semen decoction pieces(raw persicae semens, processing persicae semens, stir-baked persicae semens). The software "Chinese medicine chromatographic fingerprint similarity evaluation system(version 2012.130723)" was used similarity evaluation, and the statistical software SIMCA was used to PLS-DA. RESULTS The fingerprint of raw persicae semens, processing persicae semens, stir-baked persicae semens all contained eight common peaks. The fingerprint of persicae semen seed coat contained six common peaks. And the similarity of fingerprints were >0.90. The statistical results showed that the fingerprints before and after processing could be clearly distinguished, and revealed the four potential marker peaks that contributed most to this distinction. CONCLUSION The method is accurate and stable, which not only reflects the difference of persicae semen decoction pieces before and after processing, but also provides some reference for clinical medication and quality control of persicae semen decoction pieces.