Some correlation between a grain resistance and tensile force that influeces a grain can make it possible to determine electrostriction forces. These forces result from the external influence of an electrostatic field on a seed-grain. The paper presents a laboratory stand and research results of the tensile force and electrostatic field influence on wheat grain resistance values. A testing machine constructed at the Department of General Electrical Engineering, Lublin Technical University was used for the experiments. An insulated meter was used to measure grain resistance values and a system of bridge, a strain gauge and an A/D converter was used to measure the force. "Sigma" spring wheat seed grains were the experimental samples 5 measuremental series at forces within the range: 0 to 17N were carried out during tensile tests of grains. The results indicate a distinctive dependance of wheat grain resistance values on the tensile force. Some insignificant decrease of grain resistance values was observed during the initial phase of force raise (the range between 0 and 2N). Then a constant resistance increase at the time of force raise was observed. The highest change of resistance occurred within the final stage of tensile test, i.e., within the range: 10 to 17N. When the force of 17 N was reached the grain was damaged (a tensile failure). Seed resistance values depend on the electric field intensity. When it grows the resistance decreases and is approximately linear. The maximum change of about 5.5% occurred when the field increased from 0 to 5 kV/cm.