The research on the conversion of replacement forests was launched on the theoretical as well as the practical level. The theoretical part focused on different methods of conversion that are applied in Europe. Natural regeneration is an important prerequisite for the feasibility of conversion. The practical part analysed the regeneration in the forest district Krašica which is placed in the mountainous vegetational belt of the Savinja Alps (Slovenia). The research was based on the site type with Wood Fescue (Festuca altissima All.) at the site Homogyno sylvestris-Fagetum. A sample of 83 research squares was put into four research objects and different silvicultural approaches were handled (different ages of gaps, different sizes of gaps, exclosure, different silvicultural measures). Main causes for low densities of regeneration manifested themselves: a strong competition of the herbal layer, scarcity of seed-bearing trees by beech (Fagus sylvatica L.)and silver fir (Abies alba Mill.), browsing by large herbivores and insufficient light conditions in small stand gaps. The adequate size of stand openings on the investigated site varies between 0,05 ha and 0,10 ha. We recommend a combined method of conversion (advance regeneration + underplanting of desired tree species), individual protection of broadleaf saplings and consistent tending.