提出用改进单纯形法估计Weibull分布及其变型模型的参数 ,并通过直径和树高分布的实验拟合 ,经χ2 检验 ,其拟合效果优于传统的拟合方法。说明拟合方法的选择比改变其形式更重要 ,改进单纯形法 ,丰富了Weibull分布参数估计方法 ,提高了其拟合效果 The parameters of the Weibull distribution and its modified model are estimated by the improved simplex method. The fitting results of diameter and height distribution are better than the traditional fitting by χ2 test. It shows that the choice of fitting method is more important than changing its form, and the simplex method is improved, which enriches the Weibull distribution parameter estimation method and improves its fitting effect