The aim of this study was to evaluate the quality of harvested green mass, ensiled mass and hay from Romanian cultivars of berseem clover Trifolium alexandrinum 'Viorel' and red clover Trifolium pratense 'Select 2', grown in an experimental field of the National Botanical Garden (Institute), Chişinău, Republic of Moldova. It was determined that the dry matter nutrient content of the harvested mass varied among the clover species: 145-169 g/kg CP, 232-279 g/kg CF, 89-100 g/kg ash, 252-302 g/kg ADF, 422-479 g/kg NDF, 31-51 g/kg ADL, 140-222 g/kg TSS, 221-251 g/kg Cel, 170-177 g/kg HC with nutritive and energy values 65.4-69.2 % DDM, RFV=127-153, 12.84-13.52 MJ/kg DE, 10.54-11.10 MJ/kg ME and 6.56-7.12 MJ/kg NEl. The hay prepared from Trifolium species contained 168-183g/kg CP, 244-289 g/kg CF, 95-106 g/kg ash, 265-303 g/kg ADF, 415-437 g/kg NDF, 34-47 g/kg ADL, 113-161 g/kg TSS with 65.3-68.3 % DDM, RFV=139-153, 12.82-13.36 MJ/kg DE, 10.53-10.97 MJ/kg ME and 6.54-6.98 MJ/kg NEl. The nutrient content of ensiled clovers mass was: 147-206 g/kg CP, 226-266 g/kg CF, 112-159 g/kg ash, 239-283 g/kg ADF, 422-452 g/kg NDF, 29-43 g/kg ADL, 106-153 g/kg TSS, 210-250 g/kg Cel, 159-183 g/kg HC, 66.9-70.3 % DDM, RFV=138-155, 13.11-13.72 MJ/kg DE, 10.76-11.26 MJ/kg ME and 6.74-7.28 MJ/kg NEl The fresh and ensiled clover mass substrates for anaerobic digestion had optimal C/N=14-22 and biochemical methane potential varied from 327 to 375 l/kg ODM.