i know that when a conducting body is kept in an electric field, the field inside the body becomes zero and electric field lines are always perpendicular to the surface of body(near the surface). so what would be the answer for same case but with a NON CONDUCTING body ?

For a nin-conducting body we look at its dielectric constant.

(Actually a conductor is a body with dielectric constant = infinity.)

So, in a field the dipoles of the body align themselves with the field. Now, in case of conductors the electric field of dipoles is cancelled out by the external field (hence field=0) but in non -conductors the dipoles cannot completely compensate the external field and hence the field is reduced in proportion to dielectric constant but not to zero. 

what about the electric field lines near the surface ??? are they perpendicular to the surface??