Abstract: The reliability, optimum age and genetic gain of early selection were studied on the basis of analysis of individual growth process, the competition and the differentiation in the plantations of Pinus tabulaefortnts Carr. By using 263 sample stem data. 85 % of over-15 years old dominants in the plantations and 81 % in natural stands reached or passed the age when the growth rate was maximum in the process. Differentiation in sample plots was most violent at the age of 3 to 9. All the correlations between ages after 15 were prominent. The suitable age for selection was later than 12-15.

Key words: Pinus tabulaeformis Carr., Early selection, Genetic gain