The flora of Çekmece Nuclear Research Enstitute (İstanbul) and its environs has been investigated. This area is situated on the Europe side of İstanbul. This study has been carried out betvveen 2003-2005. at the end of this study 63 families, 241 genera and 411 taxa are identified. The endemic plants taxa are 4 and its rate is 0.98%. The plıytogeographic rates are as follovvs: Mediterranean 21.7%, EuroSibirean 11.7% and Irano-Turanien 0.7%. The rates are phytogeographically unknovvn or cosmopolitan and rates of them are 65.9%.