From the aerial parts of Scyphiphora hydrophyllacea Gaertn. F., a new iridoid glucoside dimer scyphiphin D (1) and a known iridoid glucoside geniposidic acid (2) were isolated. The structure of this new compound was determined on the basis of HR-FAB-MS, IR, (1)H and (13)C NMR (DEPT), and 2D NMR (HMQC, HMBC, COSY, ROESY) spectral data.