C#：
  
  string w3NameSpace = "http://www.w3.org/2000/xmlns/";
  System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
  
  //创建根节点
  System.Xml.XmlNode root = doc.CreateNode(System.Xml.XmlNodeType.Element, "w", "wordDocument", "http://schemas.microsoft.com/office/word/2003/2/wordml");
  System.Xml.XmlAttribute xa;
  xa = doc.CreateAttribute("xmlns", "v", w3NameSpace);
  xa.Value = "urn:schemas-microsoft-com:vml";
  root.Attributes.Append(xa);
  
  //为节点添加属性
  xa = doc.CreateAttribute("xmlns", "w10", w3NameSpace);
  xa.Value = "urn:schemas-microsoft-com:office:word";
  root.Attributes.Append(xa);
  
  xa = doc.CreateAttribute("xmlns", "SL", w3NameSpace);
  xa.Value = "http://schemas.microsoft.com/schemaLibrary/2003/2/core";
  root.Attributes.Append(xa);
  
  xa = doc.CreateAttribute("xmlns", "aml", w3NameSpace);
  xa.Value = "http://schemas.microsoft.com/aml/2001/core";
  root.Attributes.Append(xa);
  
  xa = doc.CreateAttribute("xmlns", "wx", w3NameSpace);
  xa.Value = "http://schemas.microsoft.com/office/word/2003/2/auxHint";
  root.Attributes.Append(xa);
  
  xa = doc.CreateAttribute("xmlns", "o", w3NameSpace);
  xa.Value = "urn:schemas-microsoft-com:office:office";
  root.Attributes.Append(xa);
  
  xa = doc.CreateAttribute("xmlns", "dt", w3NameSpace);
  xa.Value = "uuid:C2F41010-65B3-11d1-A29F-00AA00C14882";
  root.Attributes.Append(xa);
  
  xa = doc.CreateAttribute("xmlns", "space", w3NameSpace);
  xa.Value = "preserve";
  root.Attributes.Append(xa);
  
  //为节点增加值
  System.Xml.XmlNode body = doc.CreateNode(System.Xml.XmlNodeType.Element, "v", "body", "urn:schemas-microsoft-com:vml");
  System.Xml.XmlNode childNode = doc.CreateNode(System.Xml.XmlNodeType.Element, "o", "t", "urn:schemas-microsoft-com:office:office");
  childNode.InnerText = "欢迎光临【孟宪会之精彩世界】";
  
  //添加到内存树中
  body.AppendChild(childNode);
  root.AppendChild(body);
  doc.AppendChild(root);
  
  //添加节点声明
  System.Xml.XmlDeclaration xd = doc.CreateXmlDeclaration("1.0", "UTF-8", "yes");
  doc.InsertBefore(xd, doc.DocumentElement);
  
  //添加处理指令
  System.Xml.XmlProcessingInstruction spi = doc.CreateProcessingInstruction("mso-application", "progid=\"Word.Document\"");
  doc.InsertBefore(spi, doc.DocumentElement);
  
  //查询节点
  System.Xml.XmlNamespaceManager nsmanager = new System.Xml.XmlNamespaceManager(doc.NameTable);
  nsmanager.AddNamespace("w", "http://schemas.microsoft.com/office/word/2003/2/wordml");
  nsmanager.AddNamespace("v", "urn:schemas-microsoft-com:vml");
  nsmanager.AddNamespace("o", "urn:schemas-microsoft-com:office:office");
  System.Xml.XmlNode node = doc.SelectSingleNode("w:wordDocument/v:body/o:t", nsmanager);
  Response.Write(node.InnerText);
  
  node.InnerText = "欢迎光临【孟宪会之精彩世界】:http://dotnet.aspx.cc/";
  
  //创建CDATA节点
  System.Xml.XmlCDataSection xcds = doc.CreateCDataSection("【孟宪会之精彩世界】");
  node.ParentNode.InsertAfter(xcds, node);
  
  Response.Write(xcds.InnerText);
  
  doc.Save(Server.MapPath("test.xml"));

VB.net

Dim w3NameSpace As String = "http://www.w3.org/2000/xmlns/"
Dim doc As New System.Xml.XmlDocument

'创建根节点
Dim root As System.Xml.XmlNode = doc.CreateNode(System.Xml.XmlNodeType.Element, "w", "wordDocument", "http://schemas.microsoft.com/office/word/2003/2/wordml")
Dim xa As System.Xml.XmlAttribute
xa = doc.CreateAttribute("xmlns", "v", w3NameSpace)
xa.Value = "urn:schemas-microsoft-com:vml"
root.Attributes.Append(xa)

'为节点添加属性
xa = doc.CreateAttribute("xmlns", "w10", w3NameSpace)
xa.Value = "urn:schemas-microsoft-com:office:word"
root.Attributes.Append(xa)

xa = doc.CreateAttribute("xmlns", "SL", w3NameSpace)
xa.Value = "http://schemas.microsoft.com/schemaLibrary/2003/2/core"
root.Attributes.Append(xa)

xa = doc.CreateAttribute("xmlns", "aml", w3NameSpace)
xa.Value = "http://schemas.microsoft.com/aml/2001/core"
root.Attributes.Append(xa)

xa = doc.CreateAttribute("xmlns", "wx", w3NameSpace)
xa.Value = "http://schemas.microsoft.com/office/word/2003/2/auxHint"
root.Attributes.Append(xa)

xa = doc.CreateAttribute("xmlns", "o", w3NameSpace)
xa.Value = "urn:schemas-microsoft-com:office:office"
root.Attributes.Append(xa)

xa = doc.CreateAttribute("xmlns", "dt", w3NameSpace)
xa.Value = "uuid:C2F41010-65B3-11d1-A29F-00AA00C14882"
root.Attributes.Append(xa)

xa = doc.CreateAttribute("xmlns", "space", w3NameSpace)
xa.Value = "preserve"
root.Attributes.Append(xa)

'为节点增加值
Dim body As System.Xml.XmlNode = doc.CreateNode(System.Xml.XmlNodeType.Element, "v", "body", "urn:schemas-microsoft-com:vml")
Dim childNode As System.Xml.XmlNode = doc.CreateNode(System.Xml.XmlNodeType.Element, "o", "t", "urn:schemas-microsoft-com:office:office")
childNode.InnerText = "欢迎光临【孟宪会之精彩世界】"

'添加到内存树中
body.AppendChild(childNode)
root.AppendChild(body)
doc.AppendChild(root)

'添加节点声明
Dim xd As System.Xml.XmlDeclaration = doc.CreateXmlDeclaration("1.0", "UTF-8", "yes")
doc.InsertBefore(xd, doc.DocumentElement)

'添加处理指令
Dim spi As System.Xml.XmlProcessingInstruction = doc.CreateProcessingInstruction("mso-application", "progid=""Word.Document""")
doc.InsertBefore(spi, doc.DocumentElement)

'查询节点
Dim nsmanager As New System.Xml.XmlNamespaceManager(doc.NameTable)
nsmanager.AddNamespace("w", "http://schemas.microsoft.com/office/word/2003/2/wordml")
nsmanager.AddNamespace("v", "urn:schemas-microsoft-com:vml")
nsmanager.AddNamespace("o", "urn:schemas-microsoft-com:office:office")
Dim node As System.Xml.XmlNode = doc.SelectSingleNode("w:wordDocument/v:body/o:t", nsmanager)
Response.Write(node.InnerText)

node.InnerText = "欢迎光临【孟宪会之精彩世界】:http://dotnet.aspx.cc/"

'创建CDATA节点
Dim xcds As System.Xml.XmlCDataSection = doc.CreateCDataSection("【孟宪会之精彩世界】")
node.ParentNode.InsertAfter(xcds, node)

Response.Write(xcds.InnerText)

doc.Save(Server.MapPath("test.xml"))