This research presents the results of the study of seeds quality of two Polish native species of the genus Betula L. (Betula pendula Roth and Betula obscura Kotula), growing on the semi-natural (low human activities) and anthropogenic (high human activities) habitats. In this study the generative phase has been investigated to find differences between studied taxa and try to find out why population of B. obscura is very rare. In this research we have checked the quality of the seeds from B. obscura and B. pendula and test the survival of seedlings sowed into the ground researched in laboratory conditions. Results of germination capacity shown significant difference between trees from the anthropogenic and semi-natural sites; the energy capacity indicated significant difference between trees: B. pendula and B. obscura from all study areas. Mixed-model ANOVA/MANOVA for seedlings growth showed statistically important effects of factors (species, area, months). The results show that B. obscura grows better on the anthropogenic habitats than B. pendula, but the latter had more of the fully developed seeds and higher germination and seeds energy capacity.