Let $\overline {K}$ be an algebraic closed field of characteristic zero, and $\mathfrak{h}$ be an absolute height on $\overline{K}$. Suppose that $f(x,y)$ is an irreducible polynomial in $\overline{K}[x,y]$ and $a,b\in \overline{K}$ satisfies $f(a,b)=0$. We explicitly describe the relation between $\mathfrak{h}(a)$ and $\mathfrak{h}(b)$ by ${\rm tdeg}(f)$ and $\mathfrak{h}(f)$.