The elaboration of new effective and ecologically friendly regulators improving growth and increasing yield of oilseed rape is an actual problem for modern agriculture. Our work was devoted to screening of new effective plant growth regulators among chemical low molecular weight heterocyclic compounds, derivatives of oxazole and oxazolopyrimidine to improve the germination of seeds and growth of seedlings of oilseed rape (Brassica napus L.) of cultivar Kalinivsky. As a result of the conducted experiments, the most effective synthetic compounds that showed a high stimulating effect when used in concentration 10-9M on the growth of 21st-day-old oilseed rape seedlings were selected. It was found that biometric indices of 21st-day-old oilseed rape seedlings grown on the 10-9M solution of derivatives of oxazole and oxazolopyrimidine were increased by an average to 11 - 30 % – by length of shoots, by an average to 8 - 68 % – by total number of roots, and by an average to 5 - 43 % – by total length of roots, as compared with similar indices of 21st-day-old oilseed rape seedlings grown on the distilled water (control) or on the 10-9M solution of plant hormones auxins IAA (1H-Indol-3-ylacetic acid) and NAA (1-Naphthylacetic acid). The content of photosynthetic pigments in the leaves of 21st-day-old oilseed rape seedlings grown on the 10-9M solution of derivatives of oxazole and oxazolopyrimidine was increased by an average to 14 - 20 % – by content of chlorophyll a, by an average to 15 - 21 % – by content of chlorophyll b, by an average to 16 – 18 % – by content of chlorophyll a+b, as compared with similar indices of 21st-day-old oilseed rape seedlings grown on the distilled water (control) and were increased by an average to 14 - 26 % – by content of carotenoids as compared with similar indices of 21st-day-old oilseed rape seedlings grown on the distilled water (control) or grown on the 10-9M solution of IAA and NAA, respectively. The obtained results confirmed the possibility of using of derivatives of oxazole and oxazolopyrimidine as new effective regulators to improve oilseed rape growth.