We consider here the structure of rotating compact objects endowed wit
h a magnetic field in general relativity as models of pulsars. We disc
uss the structure of rotating stars in the framework of Hartle, taking
different realistic equations of state, and study their effects on bu
lk properties of stars. We consider the possibility of rotating stars
with a quark matter core. We also analyse the structure of the magneti
c field in the interior of the star, as affected by different equation
s of state, as well as due to rotation.