Abstract: Using the high quality broken rice as raw material,the effect of substrate concentration,enzymatic hydrolysis time,enzymatic hydrolysis temperature and enzyme concentration on the degree of hydrolysis( DE value) was systematically studied by single factor experiments. Box- Behnken design and response surface analysis,then the enzymatic hydrolysis parameters were optimized,and the basic material of mid- aged and older nutritious rice cereal was prepared combined with spray drying technology.In the conclusion,the optimal hydrolysis conditions were established as follows: substrate concentration 13%,enzymatic hydrolysis time 42 min,temperature69 ℃,enzyme concentration 0.34%. Under the optimum enzymatic hydrolysis conditions,the dextrose equivalent reached to 33.02%,moreover,there was no residual enzyme activity,and the starch digestion index was 50.62%,which was higher compared to the non- enzymatic productions by 21.71%.