The Family chapter of Civil Code was amended in 1996. It is the child's best interests that should be emphasized when the court decides whom to grant the custody of children. Moreover, in accordance with Article 41 of the Child Welfare Act, when parents divorce, the court may ex officio appoint or change the guardian of the children, provided that the decision is made for the best interests of the children. Meanwhile, parents, the competent authorities, and other stakeholders can also appeal to the court for re-appointment of a custodian. So, you may file such a lawsuit. If the court rules that your husband is unsuitable, you may be granted custody of children.