The aim of this study was to compare the chemical composition, in vitro gas production, metabolizable energy (ME) organic matter digestibility (OMD), relative feed values (RFV) of the legume forages from alfalfa, blackdisk medick, burr medic, yellow sour-clover, yellow sweet-clover, white sweet-clover, sainfoin, hairy vetch and birdsfoot trefoil. Gas production were determined at 0, 3, 6, 12, 24, 48, 72 and 96 h and their kinetics were described using the equation y=a+b(1-e(-ct)). There were significant differences among legume grains in terms of chemical composition (P<0.05). The crude protein content of legume forages ranged from 14.89 to 19.11%; ether extract from 1.08 to 3.07%; crude ash from 5.75 to 8.05%; neutral detergent fiber (NDF) from 38.27 to 46.19%; acid detergent fiber (ADF) from 28.39 to 37.79% and acid detergent lignin (ADL) from 8.03 to 15.14%. Chemical composition had a significant effect on the gas production kinetics and estimated parameters (P<0.05). Total gas production ranged from 67.6 to 76.7 ml/200 mg DM, ME from 9.3 to 11.1 MJ/kg DM, organic matter digestibility (OMD) from 65.5 to 78.3% and relative feed values (RFV) from 120.3 to 159.9. As a result of research it has been determined that the total gas production, ME, OMD and RFV of hairy vetch and burr medic were significantly higher than the other legume forages (P<0.05).