The relationship between the distribution of benthic foraminifera with ostracoda and sediment type and geochemical environment in the Iznik Lake is discussed. The microfauna (benthic foraminifer and ostracod) were sampled in seven recent bottom sediment samples, and geochemical variables of the sediment of the same samples were measured. This study is aimed at investigating the geochemical properties of 7 bottom sediment samples analysed in 5 lines in Iznik Lake. The depths for the samples varies from 1 to 68 m. The microfauna individuals were found in very low quantity, a total of 5 species foraminifera and 11 species 10 genus ostracod were identified. The geochemical properties were found to correspond well to the sediment type and depositional environment and five different sediment/ depositional environment types could be distinguished. The individuals of microfauna reveals specific faunal assemblages that are closely related to these sediment and geochemical environment types. According to the survey, sediments encountered in the formation of gypsum crystals feature when considered together with the magnetism of Iznik Lake and the surrounding area suggest that are affected by new tectonics. Again this geochemical study the magnetic properties of the heavy-mineral contents, the entire amount of magnetite and hematite and heavy-mineral content has appeared to be affected by changes in the process. The purpose of this work is to distinguish the natural (geogenic) component, originated by techtonical origin this lake, from anthropogenic contamination owing to human activity. There were relationship between microfauna assemblages and heavy metals, trace element pollutant in the bottom lake sediments. Additionally, less individuals are found in most of the sediment samples in observed (in this 7 samples), this coincidence suggests that the heavy metals within the environment can also be a cause. The reason that of heavy metals, trace element pollutants are a factor in the distribution of microfaunal assemblages of genera and species were observed. (C) 2017 Published by Elsevier Ltd.