In order to study thinning effects of beech stands on Brezova reber research three blocks with three plots within each block were set up by us. Following treatments were randomly selected for each plot within all block: classical selective thinning (treatment A), selective thinning with fixed crop trees (treatment B), control plot for natural development (treatment C). In spring 2011 the trees on plots were measured by us. Then starting points on the plotswere analyzed, the crop trees and their competitors were selected. The differences between the blocks were found out small, while within the block are being considerable. Moreover, the differences between treatments A and B in the number of selected competitors per crop tree and in the share of the competitors in total stem number were established by us.