Rheological properties of some cooked foods and factor affecting the processability of food ingredients such as the spinnability of soybean proteins for edible fiber, a non-thermally gelation of bovine whey proteins, the gelatinization and retrogradation of starch and starchy foods were investigated. The spinnability of isolated soybean proteins was influenced by the viscoelastic properties of dope, and the frequency dependencies of G' and G" for the dopes were observed for the evaluation of the ability. The non-thermal gelling ability of whey proteins was also discussed. There was a good relationship between the sensory evaluation of firmness and the elastic modulus for starchy food "Dango". The retrogradation process of starch and starchy food during storage could be described by the kinetics using a rheological parameter, and it was strongly suggested that the anti-firming ability of sugars was introduced by the structure-making effect for water.