A composite beverage was developed from milk with the addition of rice bran protein. Its formulation was optimized by one-factor-at-a-time and orthogonal array design to obtain the best sensory quality and emulsion stability. Meanwhile the storage stability of the composite beverage was investigated. The optimal formulation was found to consist of 2% whole milk powder, 0.7% rice bran protein, 10% white sugar, 0.3% citric acid and 0.2% composite stabilizer. The resulting product had a delicate taste and high nutritive value, and its emulsion stability and protein content were 97.52% and 1.0%, respectively.