The seed viability of 86 acessions of fodder grasses: awnless brome (Bromopsis inermis (Leyss.) Holub.), orchardgrass (Dactylis glomerata L.), Timothy grass (Phleum pretense L.), crested wheat grass (Agropyron cristatum (L.) Gaertn.), clustered wheat grass (Agropyron desertorum (Fisch. ex Link) Schult. et Scult.f.), annual ryegrass (Lolium multiflorum Lam.), perennial ryegrass (L. perenne L.), red fescue (Festuca rubra L.), meadow fescue (Festuca pratensis Huds.), gigantea fescue (Festuca gigantea (L.) Vill.), blue fescue (Festuca inarmata Schur. (Festuca amethystina (Hack. ex Boiss.) St.-Yves)), tall fescue (Festuca arundinacea Schreb.), tall oat-grass (Arrhenatherum elatius (L.) P. Beauv. ex J. S. et K. B. Presl.), slender wheat grass (Roеgneria trachycaulon (Link) Nevski), creeping bent grass (Agrostis alba L.), redtop (Agrostis gigantea Roth.), which were stored under controlled temperature and moisture content 3 – 6 % was investigated. It has been determined that the seeds of these species have different longevity at different storage temperatures under the genebank conditions. Phleum pretense, Phleum pretense, Agropyron cristatum, Lolium multiflorum Festuca rubra seed viability was without changing after storage at temperature 4oC for 10 years and longer. The best seed longevity of grasses were achieved when the seeds are kept at –20oC. Accessions features of different grasses species seed storage are discussed.