The leaves of Combretum quadrangulare Kurz. collected in Long An Province were chemically investigated using multiple chromatographic methods. Four compounds, 5-hydroxy-3,7,4′-trimethoxyflavone (1), ayanin (2), kamatakenin (3), and luteolin (4) were isolated and elucidated. Their chemical structures were elucidated by comparing their spectroscopic data with those in previous reports. Compounds 1 and 4 was obtained for the first time in Combretum quadrangulare.