OBJECTIVE：To esta blish a UPLC fingerprint of Pyrrosia petiolosa from southwest China ，and to determine the contents of 4 kinds of phenolic acids （neochlorogenic acid ，caffeic acid ，chlorogenic acid and cryptochlorogenic acid ）. METHODS：The determination was performed on Waters Cortecs T 3 C18 column（100 mm×2.1 mm，1.6 μm）with mobile phase consisted of methanol- 0.1％ phosphoric acid （gradient elution ）at the flow rate of 0.35 mL/min. The detection wavelength was set at 326 nm. The column temperature was 30 ℃，and injection volume was 1 μL. UPLC method was used to establish the UPLC fingerprint of P. petiolosa in combination with the Similarity Evaluation System of TCM Chromatographic Fingerprints （2012 edition）. Cluster analysis and principle component analysis （PCA）were performed by using SPSS 20.0 software. The contents of 4 kinds of phenolic acids in 20 batches of P. petiolosa were determined by external standard method. RESULTS ：There were 9 common peaks for the UPLC fingerprint of P. petiolosa . Peaks 1，3，4，5 and 9 were identified as neochlorogenic acid ，caffeic acid，chlorogenic acid ，cryptochlorogenic acid and isochlorogenic acid C ，respectively. RSDs of the relative retention time of each peak in different batches of P. petiolosa were 0-0.68％，and the RSDs of the relative peak area were 0-62.35％. The similarities between the fingerprint of 20 batches of medicinal materials and the control chromatogram were not less than 0.990. The result of cluster analysis showed that P. petiolosa from different regions could be sorted into three species. Results of PCA showed the differences among P. petiolosa from different regions. The linear range of neochlorogenic acid ，caffeic acid ，chlorogenic acid and cryptochlorogenic acid were 0.61-61.41，0.18-17.60，2.00-200.11，0.62-61.51 μ g/mL （R2＞0.999 9）. RSDs of precision ， reproducibility and stability tests were all lower than 2.00％. The recoveries were 96.23％-98.17％（RSD＝0.96％-2.28％， n＝6）. Among 20 batches of samples ，the contents of above 4 kinds of phenolic acids were 0.385 3-1.891 9，0.018 0-0.129 5，2.569 5-10.676 0，0.563.5-1.860 5 mg/g. CONCLUSIONS ： The established UPL C fingerprint could reflect the main chemical constituents of P. pedunculata . Phenolic acids could be used as the main evaluation indexes for the quality of P. petiolosa . The quality order of P. petiolosa from southwest China was Chongqing product＞Sichuan product ＞Guizhou product.