Special attention was paid for presowing seed preparing with the use of laser rays to increase sugar beet yield using economical and environment-safety methods. The field investigations aiming at determination • of influence of laser exposure of seeds on biometric features, yielding and some of chemical constitution elements were carried out. The experiments were performed for two varieties (PN Mono 1, PN Mono 4) and for 0, 1, 2, 3, 4 times laser exposures of seeds with the use of helium-neon HNA-188 laser of power of 40 µW. The exposures were accomplished during free-fall of seeds through divergent laser beam. The investigation results show beneficial effect of laser exposure of seeds on sugar beet yielding. The leaves yield ranged from 35.6 t/ha (control combination- 0) to 42.0 t/ha (4 times exposure). The leaves of plants exposed to laser rays were longer and thicker. The highest roots yield were obtained after one times seeds exposure (54.6 t/ha). The beet roots growing from the seeds exposed to laser rays were longer. Seed exposure resulted in dry matter increase by 0.1-0.3%, sugar content by 0.1-0.2%, ash by 0.026-0.080% and decrease in a-amine nitrogen amount by 0.0028-0.0062%.