Fusarium oxysporum p-glucosidase catalyses the transglycosylation and reverse hydrolysis reaction in an aqueous solution, in the presence of a second nucleophile stronger than water, such as methanol. In transglycosylation, the K-m values of cellobiose for the trans reaction and hydrolysis were 138.2mM and 356.5mM respectively and the competitive role of methanol was shown. The K, value of methanol was calculated to be 1.41M. In the reverse hydrolysis the influence of the donor concentration, up to 90% w/v glucose, was investigated and the competitive role of methanol as a nucleophilic acceptor of the glycosyl moiety was also demonstrated.