A detailed characteristic of vegetation in the long-term ecological research site using quantitative methods is provided. Plant species composition, frequencies and aboveground biomass of 25 research plots are reported. Additionally, inter-species relations and spatial pattern of vegetation are analysed. Plant community at Mt. Salatin research site belongs to the association Juncetum trifidi Szafer et al. 1923 em. Krajina 1933 (alliance Juncion trifidi Krajina 1933). Main dominants are represented by Oreochloa disticha, Festuca supina and Cetraria islandica, that are evenly distri­buted throughout the plots with mean frequencies of 39%, 38% and 57% respectively. Significant correlations have been detected between several species what might imply their competition or coexistence. The mean aboveground biomass of vascular plants at Mt. Salatin was estimated to 109.4 g.m-2. At plot level, grasses (91.02 g.m-2) and Juncus trifidus (32.52 g.m-2) account for substantial proportion of the biomass. Values of constancy, frequencies and biomass amount together with an analysis of the spatial pattern contribute to a complex understanding of the vegetation structure at Mt. Salatin research site.