Abstract: Four strains contained strong degrading ability cellulose-decomposing bacteria were isolated from rotten straw, leaves, soil in corn field, and animal dung from college of animal science and medicine of Inner Mongolia Agricultural University. The diameters of the four strains were up to 3920.8, 808.8, 541.8 and 5110.56 μm respectively after seven days＇ cultivation. The degradation rate reaches peak value when pH is 6.0 or 6.5, and the highest enzymatic activity can be up to 203, 301,262 and 276 U respectively.