The purpose of researching the development characteristics of primeval forestsis to deepen the knowledge of the restoration dynamics in natural forest. In 1984 the analysis of the horizontal structure of old - growth forest remnant Rajhenavski Rog was performed on the basis of the Central European approach. In 2004 was again performed the mapping of the development phases in the southern half of the reserve on the basis of a single methodology; in 2006 the same was done also for the north half. The comparisonof the results showed big changes in the horizontal structure. During the first mapping the optimal phase prevailed, after two decades the largest area belonged to the initial phase under canopy cover. Small rejuvenation area in the primeval forest became even more obvious and comperable with the selected domestic and foreign reserves. The data analysis for different reserves showed how wide can be the range of individual development phase. A disadvantage of the method on the basis of the Central European approach is subjectivity therefore we are going to support it with measurable indicators. The results have a practical value for the sustainable management, in particular as regard guidelines for improvement of strategies and rejuvenation conditions.