直干桉在３年生时即有少数植株现蕾、开花，大量开花结实在５年以后。立地条件好，出现成熟叶、现蕾、开花结实早。直干桉从现蕾至果实成熟要占３个年头，约需２年时间。影响结实量的主要因素是家系间和家系内的差异，并与林分密度、立地条件、管理措施等有关。结实量与胸径仅在００５水平上相关，与其他生长性状的相关均未达到０１０水平。植物生长调节剂对促花有明显效果，为对照的２５倍。本文还对提高种子产量及改善遗传品质提出了对策。 Directly eucalyptus in 3 years that when a small number of plants budding, flowering, a large number of flowering in 5 years later. Site conditions are good, there mature leaves, budding, flowering strong early. Direct eucalyptus from budding to ripe fruit to account for three years, about 2 years. The main factors influencing the yield are the differences among families and families, and are related to stand density, site conditions and management measures. The correlation between stool and DBH was only at 005 level, but no correlation with other growth traits was found at 010. Plant growth regulators have a significant effect on promoting flowers, compared with 2.5 times the control. The paper also put forward countermeasures to improve seed yield and improve genetic quality.