Purified beta-Glucosidase from Fusarium oxysporum catalysed the hydrolysis and transglycosylation reactions in the presence of cellobiose and gentiobiose. The product of the latter reaction was mainly a triose. The time of incubation, pH and substrate concentration for transglycosylation reaction were optimised. Under optimal conditions, the concentration of glucose and triose reached approximately 15-20 % of the initial substrate concentration. These results suggested that beta-glucosidase from F.oxysporum is an ideal enzyme for the synthesis of triose in reasonable quantities.