The effect of growth rate on the specific gravity of East-Liaoning oak (Quercusliaotungensis Koidz.) wood was studied and statistically compared with the effect of age (ring number from the pith). Results revealed that age is a decisive factor in controlling the specific gravity of wood, while effect of growth rate on specific gravity is statistically less important. Furthermore, the effect of growth rate varies with ring width range, age, and position within one growth ring (earlywood, latewood, or the whole ring). Within narrower ring widths, specific gravity increases rapidly with increasing growth rate, then more slowly as ring width increases, and when ring width is beyond a specific range, specific gravity remains more or less constant. Growth rate shows little effect on specific gravity of juvenile wood, but with increasing age, the effect increases gradually to reach a significant level in mature wood. Growth rate does not affect specific gravity of latewood significantly, but it shows a greater effect on specific gravity of the whole ring.