XElement.GetPrefixOfNamespace gets the prefix associated with a namespace for this XElement.
using System; using System.Linq; using System.Xml.Linq; using System.Collections; using System.Collections.Generic; public class MainClass{ public static void Main(){ XElement xmlTree = XElement.Parse("<Root xmlns:aw='http://www.domain.com'/>"); string prefix = xmlTree.GetPrefixOfNamespace("http://www.domain.com"); Console.WriteLine("Prefix: {0}", prefix); } }