PURPOSE: The early selecting method of a fast growing tree capable of shortening the breeding period of a forest tree is provided. CONSTITUTION: A thing which is top 10-20% in growing speed according to a growing period by sowing a forest tree seed in a seed bed and measuring a seedling height after the hardening of a seedling hypocotyls in brown color, and a thing which is top 10-20% in the dry weight above ground by sowing a seed and measuring the dry weight above ground of a vegetated one-year plantlet, are selected. It is selected that a gibberellins content in a seedling obtained from sowing a forest tree seed is top 10-20% of seedlings. The dry weight above ground of a one-year plantlet is any one or more selected from a whole dry weight, a needle leaves dry weight, and the dry weight of stem and needle leaves. The forest tree seed is either one selected from a somatic cell derived plant or tree species having a granule seed. The forest tree seed is any one selected from a seed of pinus, a seed of willow tree species, a seed of poplar species, and a seed of larch. [Reference numerals] (AA) Volume index； (BB) Seedling dry weight(g)본 발명은 신속생장 나무의 조기 선발방법에 관한 것으로서 보다 상세하게는 임목 종자를 파종하여 발아 후 배축이 갈색으로 갈변하고 자엽이 완전히 전개된 시기 이후부터 묘고의 생장량을 길이 생장이 멈추는 시기까지 측정하여 생장기간에 따른 묘고 생장속도가 상위 20％ 이내인 것을 선발하거나 또는 임목 종자를 파종하여 생장한 1년생 묘목의 지상부 건중량을 측정하여 지상부의 건중량이 상위 20％ 이내인 것을 선발하는 것을 특징으로 하는 신속생장 나무의 조기 선발방법에 관한 것이다.
