Abstract: Hardy-Weinberg is one of the theoretical foundations of population genetics, which is not only applicable to the gene balance problem of the autosome, but also applicable to the sex-linked genes. The equilibrium problem of a pair of genes on the autosome is relatively simple and easy to be understood because it is not related to gender, whereas the sex-linked genes do not. The genetic equilibrium characteristics of sex-linked genes were described in detail, and two general formulas were given at the same time in this paper. In the process of teaching, the genetic equilibrium oscillation process of sex-linked genes can be vividly displayed by using the two formulas, and the formula input and mapping function of Excel software, so as to achieve a good teaching effect. 

Key words: sex-linked gene, Hardy-Weinberg, genetic equilibrium, formula