The objective of this study was to optimise the MAE conditions for the extraction of flavonoids from C. paliurus. RSM was employed to study the optimal temperature, extraction time, solid–liquid ratio and concentration of alcohol, which could maximise the yield of flavonoids from C. paliurus. Then, the colorimetric method with AlCl3/methanol system was used to quantify total flavonoids, which has been reported to be a simple, quick and accurate method (Zhao, Xu, & Liu, 2004). In addition, the antioxidant activity of flavonoids from C. paliurus, obtained under optimised MAE extraction conditions was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay. The chemical composition of the MAE extract was also evaluated by liquid chromatography–mass spectrometry (LC–MS) analysis.