Abstract: A method for determination of β- glucosidase activity using geniposide as substrate by amino acid colorimetry was reported. The hydrolysis conditions of geniposide with β- glucosidase and the color reaction conditions, were optimized as: hydrolyzing temperature 50℃, time 10min, pH5.0, color reaction temperature 100℃, color reaction time 10min with the volume ratio of geniposide solvent to Arg solvent 1:1.The method measurement range is 0.05～1U/ml, the linear correlationship 0.9998, the detection limit 0.02U/ml and RSD 1.5%(n=5) with the recovery rate is 99.5% to 101.1%.This method has the advantages of wide measuring range, and the determination of β- glucosidase activity.

Key words: beta glucosidase, geniposide, arginine, determination of enzyme activity