A summary of the work concerns the basic issues related to the composition process of bio-waste deposited on the municipal landfill. Study of the landfill gas composition obtained in the representative point was analyzed during the exploi-tation of the landfill in the years 2004 - 2008. During the study the quantity and the quality parameters of deposited waste, conditions of its exploitation and the time of deposition were under consideration. Particular attention was also paid to the 30 % share biodegradable waste and the development of aerobic processes during the operation of the landfill. The composition of the gas has demonstrated the domination of aerobic processes by an oxygen content within the limits of the 4,9 - 9,7 % over anaerobic processes in the downtrend content of methane to 2,3 % and 0 % carbon content.
At the end of the article some conclusions concerning mainly an inadequate density of deposited waste which results in an easy oxygen access to the surface layers of the waste.