Comparative effects of oxidant, reductant treatment and its phosphorylation on qualities and functional properties of defatted rice bran protein isolates were investigated. Effects of oxidant and reductant treatment were that essential amino acid content of protein isolates was high and its color, pepsin digestibility were good. The phosphorylated defatted rice bran protein isolated was taken by incubating sodium trimeta phosphate in aqueous solution at pH 10.5 and $35^{circ}C$ for 3 hours and its protein score was 55. Functional properties such as solubility, whipping activity and foam stability were much improved. But color, pepsin digestibility, bulk density and fat absorption were not affected by phosphorylation.