Measurements and photomicrographs of cross-sections of the grains of different winter wheat vars. are presented to show varietal differences in % cross-sectional area of starchy endosperm and factors influencing this %. Kernels with a large cross-sectional area, nearly circular cross-section, shallow crease, and thin bran and aleurone layers have the highest % cross-sectional area of starchy endosperm. The vars., named in decreasing order of % cross-sectional area of starchy endosperm, are Tenmarq, Kawvale, Chiefkan, Turkey and Blackhull. The relationship between % area of starchy endosperm and percentage of flour extraction is discussed.