Composting is environmentally sound way to convert environmental contaminants ofrnbiodegradable organic waste into resource based agricultural input material composts, usingrnmicrobial decomposition process. The study of effective microorganisms (EM) for compostingrnwas conducted in Addis Ababa City Administration Gerji compost demonstration site usingrninoculants of commercial EM, inoculated Trichoderma harzianum, and shredding and frequentrnturning composting methods to optimize the best composting methods and to compare thernphysicochemical and microbiological characteristics of matured compost between compostingrnprocess and composting methods. From all compost pile the sample were taken at the beginning,rnin the middle and at the final stage of the composting process. The mean results ofrnphysicochemical analysis of MSW feedstock observed almost all parameters have within thernrange of the optimum for composting process. Except EC (4.2-5.2 mS/cm) the remaining meanrnphysicochemical results analysis of matured compost found within the range of acceptable limitsrnset by most countries guidelines. Mean range specific values of pH, EC, %MC, OM, TC, TN, andrnC/N ratios for matured compost were: 6.9-7.0 (MC1 and MC5), 4.2-5.2 mS/cm (MC4 and MC2),rn38.6 - 48.3% (MC1 and MC3), 39.4 -45.5% (MC5 and MC1), 21.9-25.3% (MC5 and MC1), 1.4-rn1.8% (MC5 and MC2), and 12.0:1-17.3:1 (MC2 and MC1) respectively. Mean microbiologicalrncharacteristics of matured compost showed the number of bacterial and fungal colonies rangesrn9.18 X 10 6 - 1.86 X 107 cfu/g of compost and 1.27 X 10 4 -1.59 X 104 cfu/g, respectively. Fromrnthis finding six different species of fungus were found in matured compost: Alternaria sp;rnTrichoderma sp.; Aspergillus spp.; Fusarium spp.; Penicillium sp.; and Botrytis cinerea werernfound in matured compost. Practicing use of inoculants of EM and cellulolytic culture ofrnTrichoderma harzianum in MSW can facilitate the recovery of biodegradable organic wastes byrnconverting into agricultural resource based organic fertilizers through composting process andrnminimize the overflow of MSW into landfills.rnKey words: Effective Microorganisms, Municipal Solid Waste, Shredding and Frequentrnturning, Trichoderma harzianum