OBJECTIVE: To study on the chemical constituents in ethyl acetate extraction from Polygonum orientale. METHODS: By repeated silica gel chromatographic seperation and spectral analysis the structures were determined. RESULTS: Seven compounds were isolated and identified from Polygonum orientale. They were 3,5,7-trihydrochromone (I), kaempferol (II), 5,7,4'-trihydroxydihydroflavonol (III), dihydroquercetin (IV), quercetin (V), p-hydroxyphenylethanol ferulate (VI), p-hydroxyphenylethanol-p-coumaric (VII). CONCLUSION: Compounds II, III are isolated from this plant for the first time.