利用 1993年和 1994年测定数据 ,采用球果饱满种子百分率方法估算马尾松无性系种子园异交率。研究发现 8～ 9年生马尾松无性系种子园在结实初期自交率较高 ,异交水平较低。利用不同杂交组合估算的各亲本无性系在自由授粉情况下的异交率差异较大 ,两年中分别为 4 4 .7%～98.1%和 30 .8%～ 96 .8% ,平均为 73.5% (标准误差 SE=17.3% )和 6 9.2 % (标准误差 SE=2 1.3% )。异交率在无性系间变异较小 ,在无性系内不同组合间变异较大 ,前者变异系数仅为后者的35.3%～ 53.0 %。相同双亲组合的异交率在相邻两年度间差异不显著 ,并存在着显著的正相关。同时 ,还发现异交率与座果率有显著的线性正相关关系。最后对影响异交率的主要因素进行了讨论 Based on the data of 1993 and 1994, the seed rate of outcrossing Pinus massoniana seedlings was estimated using the percentage of seed full seed. The results showed that the self-fertilization rate of 8-9-year-old Pinus massoniana seed orchard in early seed setting stage was higher and the level of out-crossing was lower. The rate of outcrossing rate of each parental clone estimated by different combinations was quite different in the cases of free pollination, ranging from 44.7% to 98.1% and from 30.8% to 96.8% in two years, with an average of 73.5 % (Standard error SE = 17.3%) and 6 9.2% (standard error SE = 2 1.3%). The rate of outcrossing in the clones was smaller, and the variation among different combinations in the clones was larger. The coefficient of variation of the former was only 35.3% ~ 53.0% of the latter. The rate of outgrowth of the same parents was not significantly different between two adjacent years, and there was a significant positive correlation. At the same time, it was also found that there was a significant linear positive correlation between the rate of outcrossing and fruit set rate. Finally, the main factors that affect the rate of outreach are discussed