The results of studies on the influence of forms and doses of nitrogen fertilizers (ammonium nitrate, urea, carbamide-ammonia mixture, ammonium sulfate) on the productivity of oil flax under the conditions of the western forest-steppe are given. In the traditional system of fertilizer, oil flax is not able to provide high yields and quality products. An effective solution to this is optimization of plant nutrition due to its balance, which promotes intensive plant development, makes it possible to actively and efficiently intervene in the process of harvesting and its quality. Therefore, determining the optimal fertilizer rate for oil flax in specific soil-climatic conditions is important for obtaining stable and high yields of culture. The purpose of our research was to determine the contribution of doses and forms of nitrogen fertilizers to the productivity of flaxseed oil in the soil-climatic conditions of the western forest-steppe. The research was carried out in 2016-2018 at the experimental field of the Institute of Agriculture of the Carpathian region of NAAS in five-point crop rotation with the total area of the plant growing on a gray forest surface glued type of soil In general, four forms of nitrogen fertilizers were studied: ammonia, nitrate, carbamide-ammonia mixture, urea and ammonium sulfate, which were added in doses: N30; N45 one time; and N30 + N15 under pre-sowing cultivation and in the "fir tree" phase against the background of P30K60. The total number of variants was 16. The object of research was a variety of flax oilseed crops of breeding of the Institute of Oilseeds of NAAS. The seed sowing rate is 6 mln similar seed per hectare. According to the results of three-year studies, the effect of intensification of mineral nitrogen feed and various forms of nitrogen fertilizers on the indices of the elements of productivity and yield of flaxseed oil has been established. In particular, it was found that their use had little effect on the density change of plant stem growth. The use of nitrogen fertilizers in the dose N45 on the background of P30K60 improved plant survival (killed during the vegetation of 0.33-0.42 million pp./ha, which is 5.2-6.3 % for control, where the death observed 0.58 million ppm/ha or 8.4 %)) compared to the N30 dose (0.39-0.49 million pcs/ha). In addition, the use of the dose N45 separately (N30 under cultivation + N15 in the phase of the "fir tree") also improved the survival rate of plants (5.2-5.8 % of dead plants) compared with the simultaneous application of N45 cultivation (5.6-7.1 %) The percentage of deaths grew in control (without fertilizers) - 8.4 % against the background of P30K60 - 7.0 %. The application of various forms and doses of nitrogen fertilizers led to an increase in the control of the elements of productivity. The introduction of N45 against the background of P30K60 contributed to an increase in the number of boxes on plants, according to the variants of fertilizers, this index varied from 14.6 to 18.3 pieces per plant (10.9 - on the control, 12.9 pcs/roll - on the РК background), increasing the amount of seeds per plant by 12.7 pc. per plant, a mass of 1000 seeds per 0.2-0.3 g compared with the control and 0.1-0.2 g compared with the LCD background, where this figure was 6.8 g. On average, over the years of research, the highest productivity of flax seed of oilseed Vodograi (2,27 and 2,48 t / ha) was obtained provided the mineral fertilizer N15P30K60 was applied for cultivation in combination with carbamide feed in the phase of "fir tree" at a dose of N15. When using the nitrogen component in the form of KAS, the gain to control was 1.45 t / ha, to the background - 1.12 t/ha. In control and against the background, this indicator was 1.04 and 1.36 t/ha respectively. When using other forms of nitrogen fertilizers on the background of P30K60, lower yields of flaxseed crops were obtained (1.37-1.38 t/ha). The introduction of the N45 separately (N30 under cultivation + N15 into the "fir tree" phase) generally led to higher performance than a single application for cultivation. Among the studied forms of fertilizers, urea and carbamide-ammonia also caused a slightly higher percentage of fiber content in flax stems, however, it was within the experimental error and was not significantly increased.