Abstract: To construct a composite consortia system with higher capacity of degrading straw, two high-yield cellulose-producing fungal strains were combined with two white rot fungal strains producing high-yield ligninase into different groups. Through measuring activity of cellulase and ligninase from various combinations, optimal composite consortia system with synergistic function is produced by the activity level of screening. And effects of pH on enzyme activity of the optimal composite consortia system are studied. The results showed that, the optimal composite consortia system was the combination of Cladosporium sp GC2-2, Lentinula lateritia 939 and Auricularia polytricha 916-1 in the ratio of 1:2:2. The enzyme produced by this consortium had a high tolerance for a wide pH range and showed high activity in both alkaline and acidic conditions. The composite consortia system has comprehensive enzymatic characteristics which have potential in the application of agricultural straw waste.