Abstract: To reveal the medicinal constituents and contents of Acer truncatum flowers, the authors used high performance liquid phase chromatographic techniques to study the contents of flavonoids, quercetin, kaempferol and isorhamnetin, in different flowers of Acer truncatum. The test condition was SyncronisaQ-C18 chromatographic column, acetonitrile-0.2% phosphoric acid (40:60) as mobile phase, flow rate of 0.9 mL/min, and detection wavelength of 360 nm. The results indicated that the average content of quercetin, kaempferol and isorhamnetin was 0.696, 0.229 and 1.207 mg/g, respectively, and there were significant differences among the plants, showing that Acer truncatum flowers had further study value and potential for new product development. This method is simple and rapid, which can be used for the determination of flavonoids in Acer truncatum flowers, and provide technical support for detecting and quality control of effective components in Acer truncatum flowers.