<rootNode>
    <category name="网站">
        <item name="mainPage">www.4463.com</item>
    </category >
</rootNode>

using UnityEngine;
using System.Collections;
using System.Xml;

public class testReadXml : MonoBehaviour {
    public string xmlURL;//http://192.168.1.106/app/cfg.xml

    void Start () {
        StartCoroutine (getXML());
    }

    IEnumerator getXML(){
        WWW www = new WWW (xmlURL);
        string progress;
        while(!www.isDone){
            progress=(((int)(www.progress * 100)) % 100) + "%";
            Debug.Log (progress);
            yield return 1;
        }
        if(www.error!=null){
            Debug.Log ("loading error:"+www.url);
        }else{
            progress="100%";
            Debug.Log (progress);
            //enter complete code
            Debug.Log(www.text);
            parseXML(www.text);
        }
    }

    private void parseXML(string xmlText){
        XmlDocument xmlDoc=new XmlDocument();
        xmlDoc.LoadXml(xmlText);
        XmlNodeList nodeList=xmlDoc.SelectSingleNode("rootNode").ChildNodes;
        for(int i=0;i<nodeList.Count;i++){
            XmlElement category=nodeList[i] as XmlElement;
            Debug.Log (category.GetAttribute("name"));//output: 网站
            Debug.Log (category.InnerXml);//output: <item name="mainPage">www.4463.com</item>
            for(int j=0;j<category.ChildNodes.Count;j++){
                XmlElement item=category.ChildNodes[j] as XmlElement;
                Debug.Log (item.GetAttribute("name"));//output: mainPage
                Debug.Log (item.InnerXml);//output: www.4463.com
                Debug.Log (item.InnerText);//output: www.4463.com
            }
        }

    }

}