采用大样本调查方法，以预选优株为调查中心，分别连续调查优株所在样地内5年生钟萼木幼树个体树高、地径的生长性状，应用数理统计进行归类分析。结果表明，多年生幼树群体的树高、地径生长表型分化遵循正态分布，利用“t”检验选择法确定优株筛选的选择标准，应用所确定的选择标准筛选速生优株，共筛选优良单株2株，5年生优株与优株所在群体比较，树高和地径分别增长115.8%、82.9%和251.9%、103.7%。

The height and rooting-diameter growth characteristics of the 5-year sapling of Bretschneidera sinensis were investigated respectively in the standard sample spot of elite-trees by large sample method, with the primarily selected dominant trees as investigation center. The height and rooting-diameter growth characteristics were both classified and analyzed by mathematical statistics. The result indicated that the growth phenotypic differentiation of height and rooting-diameter in sapling colony of Bretschneidera sinensis followed the normal distribution, and 2-elite were selected with the selection criterion according to the ‘t’ determination principle. The height and rooting-diameter growth of those selected 5-year elite sapling increased by over 115.8%、82.9% and 251.9%、103.7% respectively than the average of location colony.