In June 2008 we have carried out the measurements on two research plots on Pokljuka in order to complement the analysis of the forest stand development on research plots. We have measured diameters of trees, their quality signs and on for randomly chosen trees also the height. The first measurements on these two plots were carried out in years 1949 and 1963. The size of each plot was 1 and 0,8 hectares. They belong to the older and younger spruce largetimber stand stage of development. The growing stock is on a high level: on the first research plot it amounts to 737,8 m3/ha and on the second one 823,1 m3/ha. The composition of the stands did not change in the last 50 years, it still remains even-aged and uniform forest structure. As expected the defoliation and lenght of crown have had an influence on the intensity ofthe diameter increment. The main carriers of the diameter increment are the thickest trees. The lenght of crown, the degree of defoliation and vitality differ according to social status.Vitality of trees has also been effected by the damages.