Thank for reply.

I did type these sample for my understanding. This is similar class structure I have.

dataGridView1.DataSource = objPerson; // assume person object have data.

Class Person
{
 string _lName;
 Address _address = null;

 Public string LName
 {
  get{return _lName;}
  set{_lName = value;}
 }
  
  Public Address PAddress
  {
  get{return _address;}
  set{_address = value;}
  }
}

Class Address
{
string _street;

 Public string Street
 {
  get{return _street;}
  set{_street = value;}
 }
}

This will not work, as you said I do not have readonly properties set up for address class in Person class.
Class Person
{
......
.......

 Public string Street
 {
   get {new Address().Street;}
 }
} 

Is this the way I have to modify Person class to display street in gridview? the problem doing so is, I have NHibernate set up as the DAL layer. So, Hibernate needs mapping xml file for every class. I have one xml for person and another one for Address. As you sugested, by adding readonly property to Peson class needs to modify mapping xml. So, again I need copy same mapped types from Addres xml to person xml. This is easy to add, but I'm thinking of redundancy. 

Thanks.