The paper present results of studies on organic nitrogen compounds in the peat-muck soils of the Lutra site within the moraine zone of the Mazurian Lake District representing the young-glacial areas of north-eastern Poland of great natural values. The issues raised are important for the protection of the environment and rational usability of peat soils. Free nitrogen release, in very considerable amounts in some sites, leads to a loss in the organic matter, lowering the surface and in consequence disappearance of soil. It was found that within the Lutra site there is a soligenous water supply system to habitats, which ensures the maintenance of high soil humidity. In such conditions, mineralization of nitrogen organic compounds in the soil is limited throughout the year. The content of nitrates was usually in a very small or small content range and only sporadically in the average range. Ammonia nitrogen was also released in small amounts. The results indicate an important role of habitat conditions in the transformations occurring in peat soils.