  The invariant theory of finite groups can connect the coding theory to the
number theory. In this paper, under this conformity, we obtain the minimal
generators of the rings of E-polynomials constructed from the groups related to
$\mathbb{Z}_4$-codes. In addition, we determine the generators of the invariant
rings appearing by E-Polynomials and complete weight enumerators of Type II
$\mathbb{Z}_4$-codes.
