Pure cellulose and agricultural wastes were used as sole carbon sources for the production ofrncellulase enzymes by Trichoderma isolates in both SmF and SSF, respectively. These isolatesrn(seven) were obtained from Mycology laboratory, Faculty of Life science, Addis AbabarnUniversity. Carboxymethyl cellulose (CMC) and Congo red were used to screen four isolatesrnfor their ability to produce cellulase enzymes. Cellulase production was assayed byrnmeasuring the amount of glucose released in Î¼mol/ml/min by using the DNS assay method atrn540nm. To maximize the cellulase production, the critical parameters like carbon source,rnnitrogen source, cellulose concentration, temperature and pH were optimized under SmF. Thernhighest cellulase enzyme activity was observed after 12 days of incubation on mediarncontaining, yeast extract (1%), cellulose concentration (1%) and pH (5.5) from all isolatesrnunder SmF whereas under SSF maximum cellulase enzyme was recorded between 5-11 daysrnincubation. WB, RB and WS were found to suitable for high cellulase production whereas CS,rnCP and BB relatively showed the least cellulase production in SSF. Trichoderma isolatesrnAUT1 produce the highest CMCase on WS (5.68U/g), AUT5 on rice bran (8.15U/g), AUT2rnand AUT4 on wheat bran, their enzymatic activities were 4.92U/g and 7.01U/g, respectively.rnEnzyme synthesis was repressed in the presence of glucose and fructose while it was inducedrnin the presence of maltose and lactose in SmF. The maximum amount of cellulase wasrnobserved between 55% to 65% moisture contents. It is evident from the present study, solidrnstate fermentation was better than liquid state fermentation for the production of cellulase byrnTrichoderma isolates using agricultural wastes. The cellulase enzymes produced byrnTrichoderma isolates were active at temperature ranges of 40-60oC and pH values 4.5-6.5.rnKey words:- Agricultural wastes, Carboxymethyl cellulase, Cellulase activity, DNS methodsrnand Congo red