  In this paper we compare the effects of different theories of gravitation on
the apsidal motion of a sample of Eccentric Eclipsing Detached Binary stars.
The comparison is performed by using the formalism of the Post-Newtonian
parametrization to calculate the theoretical advance at periastron and compare
it to the observed one, after having considered the effects of the structure
and rotation of the involved stars. A variance analysis on the results of this
comparison, shows that no significant difference can be found due to the effect
of the different theories under test with respect to the standard General
Relativity. It will be possible to observe differences, as we would expect, by
checking the observed period variation on a much larger lapse of time. It can
also be noticed from our results, that f(R) theory is the nearest to GR with
respect to the other tested theories.
