调试易

document.getElementById('current node id').parentNode.innerHTML

你说的TreeView是asp.net里的那个控件吗，

我现在取当前节点的值是这样取的：document.cookie=window.event.srcElement.innerText;
var s=document.cookie.split(";"); 
window.form1.TextBox1.value=s[0];父节点不知道怎么读

document.getElementById('current node id').parentNode.nodeValue;

<div >
        <asp:TreeView ID="TreeView1" runat="server">
            <Nodes>
                <asp:TreeNode Text="t1" Value="t1">
                    <asp:TreeNode Text="t1_1" Value="t1_1"></asp:TreeNode>
                    <asp:TreeNode Text="t1_2" Value="t1_2"></asp:TreeNode>
                </asp:TreeNode>
                <asp:TreeNode Text="t2" Value="t2">
                    <asp:TreeNode Text="t2_1" Value="t2_1"></asp:TreeNode>
                    <asp:TreeNode Text="t2_2" Value="t2_2"></asp:TreeNode>
                </asp:TreeNode>
                <asp:TreeNode Text="t3" Value="t3">
                    <asp:TreeNode Text="t3_1" Value="t3_1"></asp:TreeNode>
                    <asp:TreeNode Text="t3_2" Value="t3_2"></asp:TreeNode>
                </asp:TreeNode>
            </Nodes>
        </asp:TreeView>    
    </div>
protected void Page_Load(object sender, EventArgs e)
    {        for (int i = 0; i < TreeView1.Nodes.Count; i++)
        {
            TreeNode tn = TreeView1.Nodes[i];
            aa(tn);
        }
    }    public void aa(TreeNode tn)
    {
        if (tn.ChildNodes.Count > 0)
        {
            for (int i = 0; i < tn.ChildNodes.Count; i++)
            {
                tn.ChildNodes[i].ToolTip = tn.Value;
                if (tn.ChildNodes[i].ChildNodes.Count > 0)
                    aa(tn.ChildNodes[i]);
            }
        }
    }

在给你点js方面的思路<div id="TreeView1n0Nodes" style="display:block;">
这里是子节点的位置
<div>id="TreeView1n0" 这是父节点的id可以根据子节点id获得外面那个层的id：TreeView1n0Nodes
然后把Nodes这个字符串去掉 剩下的是TreeView1n0:这不就是父节点的id吗？