<i>Juniperus</i> <i>deltoides</i> is a relic Mediterranean species of the Tertiary period, included in the Red Book of the Republic of Crimea in the status of a species declining in numbers. The development of measures to maintain and preserve populations of rare and endangered species is based on the study of their seed productivity. The aim of the work is to determine the level of seed productivity and seed quality of <i>J</i><i>. </i><i>deltoides</i> in the Crimean Mountains. Research objectives: to identify the level of seed productivity, establish the proportion of full-grained seeds and assess the degree of impact of abiotic and anthropogenic factors on the studied parameters of the generative sphere. According to the methods generally accepted in forestry and geobotany, 17 trial plots were established within <i>J</i><i>. </i><i>deltoides</i> forest stands. In addition, 3 <i>J</i><i>. </i><i>deltoides</i> radishes were isolated to determine the effect of inbreeding on seed fullness. By means of one-way analysis of variance, the degree of influence of abiotic and anthropogenic factors on seed productivity and seed quality was revealed. As a result of the research, it was found that almost half (47.53%) of all individuals of <i>J</i><i>. </i><i>deltoides</i> are characterized by low seed productivity. 10,18% during the research period did not form cones at all. It is noted that one of the factors affecting the seed productivity of <i>J</i><i>. </i><i>deltoides</i> in the Crimean Mountains is the geographic confinement of the habitats of the species. In addition, it was found that the Crimean population of <i>J</i><i>. </i><i>deltoides</i> is characterized by a low proportion of full-grained seeds, which is 1,32–26,92%. The degree of anthropogenic load of the studied territories has the greatest influence on the fulfillment of <i>J</i><i>. </i><i>deltoides</i> seeds in the Crimean Mountains.