Four types of cookies (A, B, C, and D) were made by using each of the four kinds of wheat flour: A, unmodified flour; B, flour with modified starch; C, flour with modified gluten; and D, flour with modified starch and modified gluten. These cookies were made without the addition of fat and their shortness scores were evaluated by sensory tests. High scores were obtained from cookie B and cookie D. Their microstructures were similar to that of a highly shortened cookie made with a sufficient amount of fat. The dough from flour B was harder and that from flour C was softer than that from flour A. The gelatinization of wheat starch delayed as the amount of the added fat increased. The mobility of an oil-soluble free radical used as a spin probe was depressed when wheat starch was gelatinized. From these results it was proposed that the development of shortness in cookie was due to entrapment of alkyl moieties of the fat into the hydrophobic helical coils of starch molecules.