Objective: To establish an HPLC fingerprint of Angong Niuhuangwan and evaluate its quality by similarity calculation and chemical pattern recognition. Method: HPLC was uesd

the separation was performed with the mobile phase consisting of acetonitrile and 0.1% phosphoric acid aqueous solution

and the detection wavelength was set at 230 nm.The fingerprints of 10 batches of Angong Niuhuangwan were analyzed by similarity analysis

and further evaluated the quality by principal component analysis(PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA). Result: HPLC fingerprint of Angong Niuhuangwan was established

the similarity was above 0.9

and 25 peaks were recognized as common peaks

10 of them were identified by the reference substance.It was found that there were some differences among the samples from different years

and 14 differential components that causing differences in samples from different years were found by OPLS-DA. Conclusion: The established analytical method is simple

accurate and reliable.The combination of fingerprint with chemical pattern recognition can evaluate the quality of Angong Niuhuangwan well and it can provide scientific basis for quality control of this preparation.