This study aimed to determine the effect of red fermented rice and nitrite salt as natural coloring on the sensory and nutritional properties of mackerel tuna (Euthynus sp.) corned. Fish fillet was added with salt, sugar, 1.5% (w/w) red fermented rice and 2.5% (w/w) nitrite salt, then incubated at 1-2oC for 2 days until the color of the meat became dark red. Afterward, the cured meat was washed and processed into corned fish by using 0, 1 and 2% Soy Protein Isolate (SPI). The quality of corned fish were observed based on the proximate values, pH, color, microbial content, sensory evaluation, fatty acid profiles and amino acid profiles. The results show that corned fish processed with red fermented rice and nitrite salt affected the proximate value, color value and sensory evaluation. Corned fish which processed using red fermented rice produced a sharper red color and preferred by panelist than corned fish processed using nitrite. Addition of SPI affected the red color intensity of the product and increasing panelist’s pReference for the products. Corned fish contained essential fatty acids and amino acids, therefore, it can be used as a source of amino acids to meet the needs of amino acids in the body. Based on this study, corned fish processed with red fermented rice and the addition of 2% SPI was chosen as the best formulation compared to other treatments.