using System;

using System.Collections.Generic;

using System.Linq;

using System.Xml;

using System.Xml.Linq;

using System.Xml.XPath;

using System.Xml.Serialization;

using System.IO;

using System.Text;

public class Program

{

    public static void Main()

    {

        string xml = @"<Docs>

          <Doc>

          <Content>

            <![CDATA[

              <Doc xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"">

                <Header DocNumber=""1"" Description=""Desc1""></Header>

                <Poss>

                  <Pos Id=""1"" Name=""Pos1""></Pos>

                  <Pos Id=""2"" Name=""Pos2""></Pos>

                </Poss>

              </Doc>

            ]]>

          </Content>

          </Doc>

          <Doc>

          <Content>

            <![CDATA[

              <Doc xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"">

                <Header DocNumber=""2"" Description=""Desc2""></Header>

                <Poss>

                  <Pos Id=""3"" Name=""Pos3""></Pos>

                  <Pos Id=""4"" Name=""Pos4""></Pos>

                </Poss> 

              </Doc>

            ]]>

          </Content>

          </Doc>

        </Docs>";

        XmlSerializer xmlSerializer = new XmlSerializer(typeof(Doc)); 

        XDocument xDoc = XDocument.Parse(xml);

        var cdataSections = xDoc.XPathSelectElements("/Docs/Doc/Content")

            .DescendantNodes()

            .OfType<XCData>()

            .Select(x => (Doc)xmlSerializer.Deserialize(new StringReader(x.Value)))

            .ToList();

        foreach (var section in cdataSections)

            Console.WriteLine(section);

    }

}

​

public class Doc

{

    public Header Header { get; set; }

    [XmlArrayItem(typeof(Pos), ElementName = "Pos")]

    public List<Pos> Poss { get; set; }

    public override string ToString()

    {

        StringBuilder sb = new StringBuilder();

        sb.AppendLine(String.Format("Header: {0}", Header));

        sb.AppendLine("Poss:");

        foreach (var pos in Poss)

        {

            sb.AppendLine(String.Format("Pos: {0}", pos));

        }

        return sb.ToString();

    }

}

​

public class Header

{

    [XmlAttribute]

    public int DocNumber { get; set; }

    [XmlAttribute]

    public string Description { get; set; }

    public override string ToString()

    {

        return String.Format("DocNumber: {0}, Description: {1}", DocNumber, Description);   

    }

}

​

public class Pos

{

    [XmlAttribute]

    public int Id { get; set; }

    [XmlAttribute]

    public string Name { get; set; }

    public override string ToString()

    {

        return String.Format("Id: {0}, Name: {1}", Id, Name);   

    }

}