A cellulase production process was developed by growing the fungi Trichoderma reesei and Aspergillus phoenicis on dairy manure. T. reesei produced a high total cellulase titer (1.7 filter paper units [FPU]/mL, filter paper activity) in medium containing 10 g/L of manure (dry basis [w/w]), 2 g/L KH2PO4, 2 mL/L of Tween-80, and 2mg/L of CoCl2. However, beta-glucosidase activity in the T. reesei-enzyme system was very low. T. reesei was then cocultured with A. phoenicis to enhance the beta-glucosidase level. The mixed culture resulted in a relatively high level of total cellulase (1.54 FPU/mL) and beta-glucosidase (0.64 IU/mL). The ratio of beta-glucosidase activity to filter paper activity was 0.41, suitable for hydrolyzing manure cellulose. The crude enzyme broth from the mixed culture was used for hydrolyzing the manure cellulose, and the produced glucose was significantly (p < 0.01) higher than levels obtained by using the commercial enzyme or the enzyme broth of the pure culture T. reesei.