中文摘要：

赋予氨基酸编码方法下除终止子之外的密码子突变为终止子时每一位发生的变化权值，利用矩阵来表示所有的突变方式和难易程度，综合亲水性与疏水性理化性质，提出亚氨基酸编码方法，并给出该编码方法下同义密码子的相对使用度fSubtypesRelativeSynonymousCodonUsage，SRSCU）．然后选取15条H5N1序列，使用MEGA4．0分析它们的同源性，并分别在氨基酸编码、拟氨基酸编码、亚氨基酸编码这三种环境下研究所选序列使用密码子的偏好性，对比结果验证，亚氨基酸编码方法具有相应的优越性．

英文摘要：

In the amino acids coding method, sixty-one kinds of codon can change into stop codon. In this passage, the mutation of every position was endowed with weight and matrix was used to investigate the way and difficulty. Besides, hydrophilicity and hydrophobicity have also been considered in the proposal of subtypes amino acids coding. And subtypes relative synony- mous codon usage was put forward through a series of inference. Then fifteen H5N1 sequences were choosen from GenBank. MEGA4.0 helped us acquire the homology of samples. By calculat- ing their SRSCU, RSCU and QRSCU, the average codon bias in every amino acids coding method was obtained. The result of analyzing and comparing shows that the subtypes amino acids coding method is advantageous.