Crown structure transformation (formation of secondary shoots of different orders in successive series on damaged and/or defoliated branches) is a very sensitive indicators long-term tree damage process on the one hand, and of the subsequent regenerative processes on the other hand. Tree crowns on the permanent research plots, situated in air polluted Czech mountains were visually investigated and classified into several categories of crown structure transformation. One or more trees from most frequent categories were selected for investigation of the branch structure transformation. Distinct secondary shoot formation, which compensates a defoliation of primary shoots, indicates overcharging of "stress exceedance starting level". "Significant harmful effect time" can be detected by estimation of the time of termination of annual wood production of primary shoots. Trends of annual wood production time series at the branch base in relation to visually estimated health status of the shoots informs us about possible subsequent development of the tree.