The objective of the presented work has consisted in the attempt to evaluate elasticity of selected seeds, relying on the measurement of their hardness. Hardness has been measured using a modified Vickers method. During the measurement, instead of determining the indent size, maximum depth of penetrator sinking into the biological material was measured. Minimum necessary loading time was determined to be 15 minutes. The investigations of the elasticity modulus were conducted in accordance with ASAE recommendations. The conducted statistical tests indicated significant influence of the water content and kind of the material on its hardness. Existence of second order interaction between the shape factor and the water content was found. Non-linear estimation according to various models has been conducted. Relatively, the highest best fit of the theoretical curve to experimental results was obtained in the exponential model.