GPS measurements of coseismic displacements from the 1999, Chi-Chi, Taiwan earthquake are modeled using elastic dislocation theory. We find that a single fault plane cannot fit the data, but rather a curved fault surface consisting of multiple segments dipping 20--25¿ best fits the observations. The model fault exhibits reverse and left-lateral slip on a 75 km long N-S trending segment and reverse and right-lateral slip on a 25 km E-W trending segment at the northern end of the rupture. The 21¿ dipping E-W segment is inconsistent with previous interpretations of high angle tear faulting. ¿ 2001 American Geophysical Union