The objective of this research that was carried out at the Faculty of Agriculture in Zagreb in year 2013 was to determine the optimal plant density of new soybean genotypes. The study included three genotypes of soybean: varieties Ana and Gabriela and breeding line L910001 that were sown in three densities of 50, 60 and 70 plants per meter square. The results showed that each of the tested genotypes reacted differently to the three studied plant densities, but the results achieved in the majority of the attributes were not statistically different. The highest seed yield per plant was achieved in the highest density (70 plants per m2), but it was not significantly different than the yield obtained at the least density. At the lowest sowing density (50 plants per m2) were obtained the highest number of branches, the largest total number of nodes and the total number of fertile nodes per plant, the largest number of pods and number of seeds per plant and the maximum weight of seed. Plant density had no effect on plant height, height to the first node, the number of nodes on the main stem, 1000 seed weight and the harvest index. In this study, except the plant density, a significant role during the growing season had temperatures and precipitations, which differed in relation to the long term average.