Abstract: Defatted rice bran was used to extract protein by alkali method，acid method and salt method，orderly.The yield of protein in defatted rice bran extracted was a key index.The optimal extraction processing parameters were determined by orthogonal experiments through evaluating the effects of material-liquid ratio，pH value，extraction time，temperature，salt concentration of each method on the yield of protein.The results from the alkali method indicated showed that the optimal parameters of defatted rice bran were 3 h，pH 13，35 ℃，material-liquid ratio of 1∶10，and the yield of protein was 24.3%.For the acid method used，the best extraction parameters was 3.5 h，pH 0.5，40 ℃，material-liquid ratio of 1∶8，and the best yield of protein was 18.18％.For the salt extraction method ，the optimal NaCl level，temperature，material-liquid ratio of defatted rice bran were respectively 0.6 mol/L，45 ℃，material-liquid ratio of 1∶10，2.5 h，and the yield of protein was 7.86%.For the total yield of protein in rice bran extracted was 48.23% under the optimal parameters of alkali method，acid method and salt method，orderly.