Abstract: Whey powder, which was used as substrate, was fermented with Lactobacillus casei after protein clarification.The optimal conditions of the fermentation were gained by orthogonal experiment on the basis of single factor test with the scavenging effect of fermentation broth on 1, 1-diphenyl-2-picrylhydrazyl ( DPPH·) as index; then mixed the fermented whey with stabilizer and sauce together to prepare the beverage, and the optimum prescription of beverage was optimized by orthogonal experiment. Results showed that optimal conditions of the production process were as follows: Lactobacillus casei 4% , fermentation time 8h, whey 10%, fermentation temperature 41℃; xanthan gum 0.3% , orange juice 4% , sugar 6%.The final product, whose comprehensive score and scavenging effect of DPPH· were 82.6 and 47.86% respectively, was not only a yellow color but also acid fragrance.