This article (work) gives information about production of methane from 11 samples of grass silage. Production was studied in two following levels: specific methane production per 1 kg of organic total solids, specific methane production per 1 kg of fresh material.These grass silage samples were at the same time analyzed from the point of view of feeding properties and quality: protein, digestible protein, fiber, acid-detergent fiber (ADF), neutral- detergent fiber (NDF), BNVL, lactic acid, acetic acid, butyric acid, starch values, metabolizable energy, total energy, net energy lactation, net energy for fattening, pH, acidity of the water leachate mg KOH, protein PDIA, protein PDIN, protein PDIE, Na, K, P, Mg, Ca and ash. Statistic dependence was searched between feeding quality and methane production of tested samples. As statistically significant parameters influencing methane production were: lactic acid, pH, acidity of the water leachate mg KOH and total solids. Change of concentration of remaining parameters had not adequately provable influence on methane production.