Abstract: The samples collected from the progenies of a 12-year-old open-pollinated seed orchard and the individuals of a 28-year-old plantation are studied in the paper. Results show as follows: 1) The within-tree variation in wood specific gravity (SG) and tracheid length (TL) is significant. 2) The giowth both in SG and TL from the pith at the breast height is rapid and stabilizes gradually 13-18 rings after. 3) The difference in SG is 14.4 percent for 28-year-old trees unextracted and extracted and 4.5 percent for 12-year-old trees, but SG is highly correlated to unextraction and extraction. 4 ) The correlation is high between related traits of 28-yebr-old wood.