What is equivalent to clause between, for comparasion strings in LINQ or lambda expression of?

perpetrators >= and <= are not for strings. they will throw compile time error to you. you can use CompareTo for this as shown below

x.Name.CompareTo(Start) >= 0 && x.Name.CompareTo(End) <= 0

Have you tried:

yourDataContext.Country.Where(c => c.Name >= "Argentina" && c.Name <= "Jamaica");