Abstract: The β- glucosidase from Paecilomyces sp. FLH30 exhibited a broad substrate specificity. The enzyme hydrolyzed p NPG,p NP- β- D- galactoside,cellobiose,lactose,salicin,gentiobiose,exhibiting apparent kinetics constant( Km) values of 0.54,5.28,0.98,26.34,6.92 and 1.72 mmol/L,respectively.A certain concentration of glucose( 5~150 mmol/L) and xylose( 20~600 mmol/L) had an activation on the enzymes use p NPG as substrate,above the value then demonstrated inhibition.Glucuronolactone had strongly inhibited the enzyme activity,the value of inhibite constant Kiof glucose,xylose and glucuronolactone was 63.4,170.3 and 0.038 mmol / L. Xylose also had an activation on the enzyme hydrolysis of cellobiose and lactose,the enzyme activity increased by 189.6% and166.3% respectively in the xylose concentration 200 mmol / L. Furthermore,the enzyme showed transglycosylation activity and could produced cellotriose and gentibiose use cellobiose as substrate.