Acremonium cellulolyticus is a fungus that produces cellulase and has been exploited by enzyme industry. To promote cellulase production by A. cellulolyticus strain C-1, we evaluated the effects of the saccharides: Solka Floe (cellulose), soluble soybean polysaccharide (SSPS), pullulan, lactose, trehalose, sophorose, cellobiose, galactose, sorbose, lactobionic acid, and mixtures as carbon sources for cellulase production. Solka Floe with SSPS enhanced cellulase production. Lactose as the sole carbon source induced cellulase synthesis in this fungus, and the synergistic effects between lactose and Solka Floe was observed. Various enzyme activities and the protein composition of crude enzyme produced by cultures with or without addition of lactose were analyzed. The results showed that lactose addition greatly improves the production of various proteins with cellulase activity by A. cellidolyticus. To our knowledge, this is the first report on production of cellulases by lactose in the A. cellulolyticus.