In this study, the local soil conditions at Küçükçekmece-Sefaköy regions in Istanbul are investigated and a microzonation study is carried out with respect to soil amplification in accordance with the new Microzonation Manual (MERM, 2003). Within the framework of a project implemented for investigation of the region with respect to suitability for settlement, the geological and tectonic characteristics of the region were investigated with the aid of soil exploration borings. In order to be able to investigate the effects of local soil conditions on the dynamic behavior, one dimensional site response analysis are performed with the computer code EERA by utilizing the findings of field and laboratory investigations. The outcomes of the numerical analyses and emprical equations are processed by GIS techniques in order to produce microzonation maps in terms of soil amplification.