In this study physical and chemical analyses of soils were conducted in four areas of the habitat fresh mixed coniferous forest typical of the Kampinos National Park (20% forest area KPN). An attempt was made to evaluate the stock of organic carbon in every genetic horizon and the whole profiles of selected soils, and one counted the indicator ITGL (FSTI - Forest Soil Trophizm Index). In the examined soils, the particle size distributions, the content and ability to store organic carbon was analyzed as well as the amount of total nitrogen, C:N ratio, soil reaction and sorption properties. The highest content and stock of organic carbon was noted in the Brunic Arenosol (Distric) Postagricultural. In the investigated soils, the reserve of the organic carbon is accumulated in almost equal proportional shares, dividing soil into horizontal organic and mineral parts.