The objective of this study was to elaborate and apply some methods for the estimation of the mechanical properties of the seed coat. The shrinkage and its stress involved by drying or tension was collected as the shrinkage-time curve, stress-time curve, and strengthmoisture relationship. The shrinkage-time curve was obtained with strain gauge extensometer at drying process. The stress-time curve obtained with the Instron machine was based on the isometric measurement of the force induced by a shrinkage at drying. The strength-moisture relationship was formed by the collection of the strength values of the seed coat at differ moisture, based on the force-deformation curve obtained at tension. French bean and bean (Phasoleus L.) cultivars were obtained to study the effect of drying conditions on the stress and shrinkage of the seed coat. The experimental results concerning with strength of the seed coat proved that frequently the stress as was higher than its strength R_m at tension. It was observed, that moisture content is most influential factor on the strength of the seed coat at tension and increase of the moisture decreases its strength. All results of the experimental study were utilise for verification of a model describing the cracking mechanism at drying of grain legume.