The history of the study of swamps and wetlands in Galicia and Lviv region is considered. Centers of peat development in the studied region were identified. Peculiarities of swamps distribution within the plain part of Lviv region and Male Polissia were studied. Malopolissia swamps occupy 59.6 % of the total area of swamps in the plains of Lviv region. The location of the swamps is related with the wetlands of the Western Bug and Styr valleys. The region is dominated by lowland swamps with a predominance of grass groups, less common grass-moss, shrub and forest groups. Within Male Polissia, 57 peat deposits with a total area of 27.76 thousand hectares have been registered. The balance mineral reserves of peat amount to 83,339 thousand tons. The largest peatlands in terms of area and balance mineral reserves are Stoіaniv, Solokiia, Leshniv, Lviv, Smilne and Radekhiv. On the basis of topographic maps the tendencies of change of areas of swamps and wetlands in the interfluves of the Western Bug and Rata for the last 240 years are analyzed. The general trends towards the reduction of wetland areas have been noted. The process of reducing the area of swamps changed in different historical periods. Before the construction of the main canalized channel of the Western Bug, the straightening of riverbeds of Rata and Solokia, and drainage works on small rivers and streams, the level of wetlands remained high and ranged from 14.6 to 23.1%. After the channel straightening and drainage works were completed, the share of wetlands fell to 7.8% of the total area. In the past, the peatlands of Male Polissia were a valuable industrial resource: chemical raw materials, fertilizer for agriculture, fuel for household needs, and a medicinal natural resource in medicine. The primary functions of peatlands are the storage of dampness and biological diversity, and importantly, carbon dioxide. Swamps and peatlands are the most efficient ecosystems for carbon storage. Topical issues of geoecological significance of wetlands of the studied region are considered, in particular, they act as hydrological and climatic regulators, centers of greenhouse gas deposition, distribution areas of valuable and rare plant species, etc.