Objective: To optimize enzymatic hydrolysis technology of genistin. Method: Materials of genistin with different size were prepared by ultrafine grinding technology

then genistin was hydrolysised by celluse to get genistein.With the conversion rate of genistein as index

single factor tests were used to investigate effects of enzymatic hydrolysis time

temperature

size and pH on enzymatic hydrosis technology

and then

preparation technology of genistein was optimize by central composite design response surface methodology

which was enzymatic from genistin ultrafine powder. Result: Optimum technology conditions to get genistein through enzymatic hydrolysis genistin ultrafine powder were as followings:pH 5.5 acetic acid and sodium acetate anhydrous buffer as reaction medium

temperature 49 ℃

reaction time 11 h and ratio of substrate-enzyme1: 1.Under these conditions

the conversion rate of genistein was (96.47±1.12)%

which comparing with genistin ordinary powder

the conversion rate increased 1.84 folds. Conclusion: This method of enzymatic hydrolysis genistin ultrafine powder by celluse to obtain genistein was simple

efficiency and suitable for modern large-scale production.