How to deserialized xml ?

Question

hi all ,
i am creating xml file using below code

   Root = XD.AppendChild(XD.CreateElement("Root"));

                XmlNode name= Root.AppendChild(XD.CreateElement(" name "));

                XmlNode   UserName = Root.AppendChild(XD.CreateElement("UserName"));

                Root.AppendChild(Cloud);

                Root.AppendChild(CloudUserName);

                //XmlAttribute ChildAtt = Child.Attributes.Append(XD.CreateAttribute("Attribute"));

                Cloud.InnerText = test.ServiceName;

                CloudUserName.InnerText = test.UserName;

                CloudKey.InnerText = test.Password;

                XD.Save(appStartPath);

now how to do deserialization of this data?