Abstract: In order to meet the special needs of diabetics for nutrients and diet,a series of powdered diabetic nutritional formulas were designed and prepared by dry process. The formulas were optimized using sensory evaluation and sedimentation volume ratio by orthogonal test. And the glycemic index(GI)of the optimum formula was determined by in vitro and in vivo digestion test. The results showed that the formula A₃B₁C₃D₂(whey protein concentrate:soy protein isolate=14.1:7.7,resistant dextrin:soybean dietary fiber=8.25:1,xylitol:crystalline fructose=5:1,and xanthan gum 0.4)had the highest sensory evaluation score and sedimentation volume ratio. And the GI value was 45.4,which reached the low GI food standard and satisfied the requirement of diabetic food for special medical purpose. Therefore,it is expected to be developed into diabetic food for special medical purpose.