The research on the seminatural Western Carpathian grasslands (1992–2005) in Slovak
Republic with the altitude from 360 to 1150 m and inclination up to 28º, in the regions of Kysuce,
Orava, Liptov, Turiec, Považie, Horehronie, and Spiš presents 900 floristic analyses performed on 60 farms with the area of 9 712 ha. Regression and correlation analyses, namely pair coefficients of correlation and non-linear regression analysis (parabolic function), were used to study the correlation between the evaluation of the grassland quality (EGQ) and the selected factors (floristic group, leguminoses, other herbs and ferns in %, share of empty places in %, diversity of species, altitude and inclination). The progress of the correlation between the selected factors was analysed to set the optimal values EGQ. The diversity of species varied from 8 to 66 species, and the quality of the grassland (EGQ) varied from 8.50 to 85.38. A positive (direct) correlation was found out in case of two factors (% of grasses and leguminoses); while a negative (indirect) correlation was proved in case of the other factors (other herbs, empty places, number of species, altitude, exposition, and inclination).