Create XAttribute with namespace
using System; using System.Linq; using System.Xml; using System.Xml.Linq; using System.Collections; using System.Collections.Generic; public class MainClass{ public static void Main(){ XNamespace aw = "http://www.domain.com"; XElement root = new XElement(aw + "Root",new XAttribute(aw + "AnAttributeName", "Content")); } }