The Mariout Lake is considered an important natural resource for fish production in Alexandria Governorate, it has been subjected to various types of pollution, the lake acts as a receptor for domestic wastewater and industrial wastes. So this study was conducted to investigate the effect of environmental impacts and pollutants on some chemical properties of different cores of Mariout lake sediment, Surficial (0-10cm) and sub-surficial (10-20cm) sediments were collected seasonally using vertical soilsampler from different seven sites during winter, spring, summer, and autumn, 2017. The study showed that the mean values of organic matter, organic carbon total carbon, total nitrogen and total phosphorus were significantly (P<0.05) increased at site 3. Obtained results showed that the different sites and different cores had been affected the investigated chemical properties of the sediment where all theses parameters decreased with the depth. OSI values ranged from (0.41to 0.87), which indicated that the degree of pollution at all sites was considered slight pollution except for sewage site which was described as high pollution. It's concluded that the Mariout Lake is subjected to different types of pollution and organic matter is mainly of exogenous organic matter. And the control of sediment nutrient concentrations depends upon the control of exogenous pollution.