Abstract: The Gölmarmara Basin forms the northern branch of the Gediz Graben, which constitutes a series ofhorst-graben systems controlled by antithetic and synthetic normal fault steps in the Western Anatolia ExtensionalProvince. Although geology of this section is well known, it is not studied enough in terms of active tectonics andgeomorphology. The aim of this study is to reveal fault segments on the basis of Quaternary activity and structuralevolution of the Gölmarmara Fault forming the southern boundary of the basin.The NW-SE trending Gölmarmara Fault, which consists of the 7 km-long İsmetpaşa and 11 km-long Hacıbaştanlarsegments, has 26 drainage basins and 23 triangular facets in its footwall. Morphometric analyses (Smf, Vf, AF,HI, Shp, SL, Slip Rate) based on the digital elevation model were performed for these structures. According tocombined results of our morphometry and field studies, the İsmetpaşa Segment has higher uplift and activity thanthe Hacıbaştanlar Segment, and they are linked by a relay ramp developing during the evolution of a complete faultzone. It can be said that the Gölmarmara Fault, which was found to have passed through 3 phases from its formationto the present day, is an en-echelon fault similar to when it formed. Morphometric indices and field data indicatethat the Gölmarmara Fault is composed of medium-highly-active dip-slip normal fault segments and may causeearthquakes with a magnitude of Mw: 6.4. The Gölmarmara Fault, consisting of 2 geometric and 1 seismic segment,has uplift rate ranging from 0.179 to 0.518 mm/year (increasing at the center, and decreasing at the tips of the fault).These values are similar to uplift rates calculated for other active normal faults in the Gediz Graben.