Alkyl-beta-glucosides were synthesized with beta-glucosidase, from almond, in an amphiphilic phase reaction system using different water-miscible cosolvents. By means of stepwise addition of glucose, we obtained about 1.5 times higher concentration of hexylglucoside than that of normal reaction. Using the same way, octyl-, decyl- and dodecylglucoside were synthesized and their concentrations were 6.64, 5.3 and 4.48 g l(-1), respectively.