Cereal seed quality is currently determined by methods based on parameters established by applicable national standards of Ukraine. Analysis shows this methodological approach does not take into account heterogeneity of most crops and their sowing suitability.The aim and tasks of the study. To determine sowing characteristics of major cereals, to improve methods of their determination. The study objectives were to assess the seed quality in accordance with current indices and methods; to reveal additional parameters that can best characterize sowing suitability of seeds; to develop new methods for determination of germinability.Materials and methods. We studied seeds of corn hybrids and self-pollinated lines, different varieties of winter wheat and barley. Selection of seed samples and determination of their quality were carried out in compliance with State Standards 2240 and 4138 as well as with techniques of the SE “Institute of Grain Crops NAAS.”Results and discussion. We demonstrated heterogeneity of certified seeds of corn hybrids with the laboratory germinability of 92–99%. Heterogeneity was manifested in changes of the viability parameters – germinability upon cold germination, germinative power and seed productivity. Both mechanical and thermal damage of seeds during harvest and post-harvest processing was the main reason for reduction in viability. To describe heterogeneity, we developed a method for determining the seed germinability upon cold germination and proposed assessment of seed quality by indices including existing and additional parameters. Sowing characteristics of winter wheat and barley seeds were investigated; significant effects of seed size on seed vigor and germinative power were shown.We proposed a method for determining the seed quality on the basis of existing and additional parameters that best characterize sowing and yielding properties of cereals. Our method for determining the germinability using cold germination reduces the analysis time by 2–4 days. The method and new method are recommended to apply in internal control as well as in harvest, processing and pre-sowing treatment technologies of high-quality cereal seeds