The studies on clonal plant populations indicate that the proportion between clonal and sexual reproduction may be highly variable, depending on the biological characteristics of species and the ecological conditions of habitats. We focused on the genotypic diversity of Trifolium alpestre populations in Estonia. We assayed the genetic diversity, spatial genotypic structure and diversity with the use of allozyme markers. Populations revealed high levels of genotypic diversity and showed strong spatial structure of MLGs. The values of genetic diversity were moderately high. Spatially aggregated, identical genotypes spread up to 15 meters along the linear transects and in 4 m2 plots indicate extensive clonal propagation in populations. However, numerous unique and small-sized clones in transects and quadrates reflect significant contribution from the sexual reproduction. The spatially and temporarily stochastic soil disturbances have evidently opened new opportunities for the successful sexual reproduction from the permanent soil seed bank and have thus avoided the losses of genotypic and genetic diversity. The seed production in all populations during the three study years was low, in average up to 1.5-2.4 seeds per shoot. The almost total lack of seed set from all 57 bagged flower heads of genets grown in a common garden indicates that T. alpestre needs pollinators for the seed production.