<正>以经典最小二乘法为基础，详细阐述了抗差因子的选取。从抵抗粗差的角度出发，抗差最小二乘法可提高非线性模型在有粗差干扰条件下参数估计的精度。以广东森林资源调查的样本资料，对提出的方法进行了检验与应用，结果表明提出的方法具有明显的抗粗差性。

Differences of sixteen cultivated Cymbidium hybridum orchids in bud propagation ratio were studied. The results are as follows: (1) In the same proliferation medium, the means of propagation ratio is 2. 33 and the values below 2. 10 are as much as 50%, so it can not use the same medium to proliferate in the procedure of different genotype plantlets production; (2)Analyses of variance and multiple range tests show that the differences of propagation ratios in different genotype are significant or extremely significant, but different means also tend towards cluster and scatter, we can select adaptive medium to probe this rule. (3) The main factors that influence bud proliferation are the concentration of cytokinins,and the relations can be formulated by conic models. By using those models, good results can be obtained in the practice of C. hybridum plantlet proliferation.