To establish a method for the simultaneous determination of ellagic acid, quercetin, gallic acid, kaempferol, myricetin, tiliroside, salidroside, isoquercetin, chlorogenic acid, and quinic acid in the leaves, flowers, fruits, and roots of Loropetalum chinensis by ultra-performance liquid chromatography-tandem mass spectrometry, and provide references for the development and utilization of L. chinensis resources. The analysis was performed on the chromatographic column ACQUITY UPLC HSS T3 (2.1 mm×100 mm, 1.8 μm) with a gradient mobile phase of acetonitrile-0.2% formic solution at the flow rate of 0.3 mL•min. Column temperature was 30 ℃ and injection volume was 2 μL. Multiple reactive ion monitoring mode (MRM) was used in the negative ion ionization mode of electrospray ion source. The 10 active components had a good linear relationship, and the established method was stable, simple, and accurate. The 10 active components existed in different parts of L. chinensis, with significant different content. The main components in different parts of L. chinensis were polyphenols, with the highest content, followed by flavonoids. The content of 10 active components was generally high in flowers. Among them, the content of quinic acid was the highest, reaching 22.539 1 mg•g. This study elucidates the differences of active components in the same part and the different parts of L. chinensis, thereby providing basis for the research on the pharmacodynamic substances of L. chinensis and references for the comprehensive development and utilization of L. chinensis resources.