Phenolic compounds are secondary metabolites that are mainly responsible for different pharmacological activities of plant extracts. In this study, microwave-assisted extraction (MAE) variables were optimized for the extraction of phenolic compounds from Chromolaena odorata leaves by using a Box-Behnken design of response surface methodology. The concentration of polyphenols and functional characteristics of the extracts were identified by using liquid chromatography quadrupolar time-of-flight mass spectrometry and FTIR analyses, respectively. The obtained results indicated the MAE conditions for the optimal recoveries of the total phenolic content and total flavonoid content from C. odorata leaves. The results reveal that the C. odorata leaf is enriched with phenolic compounds.