c# - How to append my list elements

Question

I have a following string list

          List<string> myList=new List<string>();
           myList.Add("A");
           myList.Add("B");
           myList.Add("C");
           myList.Add("D");
           myList.Add("E");
           myList.Add("F");
           myList.Add("G");
           myList.Add("H");

           string Res=""
           foreach(String str in myList)
           {
               Res+=","+str;
            }

Is there any better method to join my List values than this ??

Thank you All