Abstract: An ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) method was developed to evaluate the chemical consistency of triterpene acids in ethanol extracts of Poria and acetic ether extracts thereof. First, high resolution mass spectrometry data were obtained with Full scan mode, by comparing with MS data from the reference compounds and literatures, a total of 23 components were unequivocally or tentatively identified in ethanol extracts and acetic ether extracts thereof. Then, a mimic multiple reaction monitoring (mMRM) mode was established using UPLC-QTOF-MS/MS to quantify the triterpene acids in ethanol extracts and acetic ether extracts thereof. Eleven components were absolutely quantified with reference compounds, while 12 components without reference compounds were relatively quantified with peak areas, the transfer and enrichment rate of triterpene acids during liquid-liquid extraction were calculated. It was found all of the 23 triterpene acids identified in Poria ethanol extracts could be transferred into acetic ether extracts with high transfer and enrichment rate. The present study provides not only scientific evidence for further extraction of triterpene acids in Poria by acetic ether, but also an approach for comprehensive evaluation of the chemical consistency of herbal medicine extracts before and after the liquid-liquid extraction.