set Check to treeView checkbox

I have a TreeView that each item has a different code.

User can check 5 items and save them. Then I have a list of treeView's nodes code.

I want to show the checked items in form load to the user. But my code doesn't work. can anybody help me?

This is my code :

private void chechTreeViewItems(List<int> remID)
    {
        foreach ( System.Windows.Forms.TreeNode item in this.tvRemark.Nodes)
        {
            for (int i = 0; i < remID.Count; i++)
            {
                if (Convert.ToInt16(item.Tag)== remID[i])
                {
                     item.Checked = true;
                }
            }

        }

    }

I think this code can't trace child nodes.