Abstract: Principal Components and Classification Analysis (PC&CA) represents one of the most utilised multivariate chemometric techniques, having the advantage to use many measurements for a single sample in the same time, being recommended for understanding better the complexity of one phenomenon. The aim of this paper was to use PC&CA to study the effects of different types of fertilizers on polyphenols content of forages harvested in autumn from permanent grassland. Gravimetrically was established the matrix of floristic composition. The experimental field was fertilized first time in 2003, organic and/or NPK mineral. The determination of polyphenols contents was made using UV-VIS SPECORD 205 spectrophotometer, in conformity to chemical Folin and Ciocalteu colorimetric method. The highest polyphenols content was identified in forages from unfertilized variant (108 μM gallic acid/g). PC&CA can be a useful tool in describing the modification of polyphenols contents of forages under the effects of organic and/or mineral fertilisation of permanent grassland.