The major problem in the drying of grain legume with heated air is the splitting of the seed coat. Temperature and moisture gradients can cause stresses in the seed coat during drying. In view of these problems, there is need, specially in the legume seed industry, to find the optimum combination of drying parameters which will minimise seed coat cracking. The objectives of this study were to apply and verify a model describing some geometrical relations for cracking mechanism at drying, and to estimate the effect of drying on the stress and strain development of the seed coat. Fababean (Vicia jaba L.), soy bean (Glicine hispida Max.), bean (Phasoleus L.), and pea seed (Pisum sativum L.) cultivars were obtained to study the effect of drying conditions on the splitting of seed coat, subjected to different drying conditions. The time-strain curves at different drying conditions were obtained with 2630-107 Instron strain gauge. Shrinkage of the seed coat at drying leads to its stress and splitting. The results obtained in all experiments concerning with strength of seed coat proved that frequently the stress σ_s was higher than strength R_m of seed coat. However, most seeds of real condition are in the layer being in contact to other. It limits inflow of air to some parts of seed coat. Hot air caused the shrinkage of part, which is only available for the stream of air. Those, shrinkage of dry part of the seed coat caused tension of wet part of it. Probably, it is one of the most important reason of the seed coat cracking during drying.