In this paper，production of single cell protein（SCP) was studied in fermentation of orange residue incomplement of 15％（w/w)bran by mixed bacteria fermentation(Aspergillus ficuun(A)，Aspergillus oryzae(B)，Endomycopsis fibuligera(C). The main factors，including inoculants ratio of mixed bacteria，inoculated quantity,cultivate temperature，substrate moisture and cultivate time，were investigated by using Response Surface Methodology（RSM) and the Face-Centered Central Composite Design（FCCCD) for the yield of soluble proteins. The results wereshown that mixed of A，B and C in the inoculants ratio 1.357:1.447:0.661，inoculation quantity 0.313 mL·g-1，cultivate temperature 26.7 ℃，substrate moisture 71.2％ and cultivate time 62.7 h were suitable for the increasing of protein content in fermentation product. The maximum yield of soluble protein was 1170.58μg/g. Furthermore，from thevalidated experiment，we found that the theory values were closed to the experimental results，and the relevent deviations were 0.276％ and 1.015％. All these data demonstrate that the RSM is suitable for the design of fermenting experiment.