  The phase transition between the nuclear matter and the quark matter is
examined. The relativistic mean field theory(RMF) is consider with interacting
nucleons and mesons using TM1 parameter set for the nuclear matter equations of
state. It is found that the trasition point depends on coupling constant
$\alpha_s$ and bag pressure. From the study of the structure of a hybrid
neutron star, it is observed that the star contains quark matter in the
interior and neutron matter on the outer perifery.
