continuing to the chemical study on hydrocotyle bonariensis comm. ex lam. we now focus on the method for extracting alkaloid compound. from the average polarity extract, two isoquinoline alkaloids as tetrahydropalmatine (1), (-)-(s)-xylopinine (2) and a carbohydrate: ethyl 2-o--fructofuranoside (3) were isolated and identified. the structures of these new compounds were elucidated based on the data of nmr, esi-ms spectroscopic techniques and comparison with the reported documents. this was the first report about these compounds on the genus hydrocotyle. the isolation research has been continued.