Lignocelluloses are comprised of cellulose, hemicellulose, and lignins, which constitute plant biomass. Since peroxidases can degrade lignins, the authors examined peroxidase Tfu-1649, which is secreted from the thermophilic actinomycetes, Thermobifida fusca BCRC 19214. After cultivating for 48 h, the culture broth accumulated 43.66 U/mL of peroxidase activity. The treatment of four types of lignocellulolytic byproducts, i.e., bagasse, corncob, pin sawdust, and Zizania latifolia Turcz husk, with Tfu-1649 alone increased the total phenolic compounds, with limited reducing sugars, but treatment with xylanase, Tfu-11, and peroxidase Tfu-1649 showed synergistic effects. Hence, the co-operative degradation of lignocelluloses by both peroxidase and xylanase could contribute to biomass decomposition and further applications in the agricultural and environmental industries.