To delineate the tectonic character of Taiwan, an island-wide gravity survey of Taiwan was conducted between 1980 and 1987. The Bouguer anomaly map shows that, in general, isogals trend NNE in consonance with the overall structural trend of the island. With seismic and other geophysical data as constraints, the subsurface density structures were modeled along three profiles across the major structural trends. The gravity data are consistent with average continental Moho depths of 26 km in the Coastal Plain and the Western Foothills, 28 km underneath the Coastal Range in eastern Taiwan, and 33 km under the Central Range. A lack of significant correlation of the Bouguer anomalies with the topography implies dynamic, rather than isostatic, support of topography in the Taiwan region. ¿ 1998 American Geophysical Union