The effect of xylose, galactose and sorbose on the production of cellulases, xylanases, lytic enzymes and beta-galactosidase by mutant ?strain Trichoderma reesei M-7 was analysed. The aforementioned sugars were used separately and in the form of mixtures with lactose as the source of carbon during continuous cultivation of mutant M-7. Feeding medium containing mixtures of xylose and lactose in the ratio of 0,25/0,75% and 0,5/0,5% induced an increased synthesis of xylanases. Increased xylanolytic activity (about 12-27%) with the xylose/glucose ratio of 0,25/0,75% and a significantly increased activity (about 2,5 fold) with the ratio of both sugars of 0,5/0,5% was observed in comparison with continuous cultivation in the presence of 1% of lactose in the medium. Reduced synthesis of all cellulolytic (FPU, ?-1,4-endoglucanase, ?-glucosidase) and xylanolytic enzymes correlated with the increased galactose concentration in the feeding medium. Galactose also repressed the production of ?-galactosidase of the mutant-strain M-7. The results obtained after continuous cultivation with sorbose and lactose showed that sorbose was a worse inducer of synthesis of cellulolytic enzymes than lactose.