本研究将试验处理分为１代种子园、优良家系、无性系、优良无性系４个改良层次。研究结果表明：改良效果依次增大。优良无性系单行小区试验，９年生材积比那坡种源增加６７．３％；块状造林，两块平均林龄８年，平均树高９．９ｍ，平均胸径１３．１ｃｍ，每６６７ｍ２林木蓄积量１７９ｍ３，比那坡种源增加９６．７％。因此，无性系选育是充分利用杉木多层次遗传变异获得最大改良效果的有效途径 In this study, the experimental treatments were divided into four generations: improved seed orchard, excellent pedigree, clones and excellent clones. The results show that the improvement effect increases in turn. The results showed that the 9-year-old plantation increased 67.3% from the provenance of Napo slope. The average height of two stands was 9.9 m with an average diameter at breast height of 13.1 cm, The amount of 179m3, than Napo provenance increased 96.7%. Therefore, clonal selection is an effective way to make full use of multi-level genetic variation of Chinese fir to obtain the maximum improvement effect