The aim of this investigation was to evaluate a share of x Festulolium loliaceum (Huds.) P. Fourn. hybrids in comparison to other species in monoculture pasture sward. The studies were carried out in the years 2002-2005 in Sosnowica on mineral and organic soil. Five species were sown in monoculture: Poa pratensis, Festulolium braunii, Festulolium loliaceum (2 strains), Lolium perenne and Festuca pratensis. Tetraploid hybrids of Festulolium loliaceum [Festuca pratensis (4x) X Lolium perenne (4x)] were bred in The Institute of Plant Genetics, Polish Academy of Sciences in Poznań. The sward was grazed by Limousine cattle 5-6 times in a growing season. The share of tested species was determined by analyzing of surface cover by the Weber method. Moreover, the quantity of sown species as well as species appearing in a monoculture in following years of utilization were determined by the Braun-Blanquet method. The results of carried researches indicate a systematical increase of the share of other species, especially herbs and weeds. Festulolium loliaceum and Lolium perenne hybridswere characterized by the highest share in the pasture sward after 4 years of utilization, Festuca pratensis by the lowest share.