XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml("<xml><description><![CDATA[木子屋:http://www.mzwu.com/]]></description></xml>");

//读取
Console.WriteLine(xmlDoc.SelectSingleNode("//description").FirstChild.InnerText);

//设置
xmlDoc.SelectSingleNode("//description").FirstChild.InnerText = "谷歌:http://www.g.cn/";

//显示
Console.WriteLine(xmlDoc.InnerXml);