  An effective theory to treat the dense nuclear medium by the perturbative
expansion method is proposed as a natural extension of the Heavy Baryon Chiral
Perturbation Theory (HBChPT). Treating the Fermi momentum scale as a separate
scale of the system, we get an improved convergence and the conceptually clear
interpretation. We compute the pion decay constant and the pion velocity in the
nuclear medium, and find their characters different from what the usual HBChPT
predicts. We also obtain the Debye screening scale at the normal nuclear matter
density, and the damping scale of the pion wave. Those results indicate that
the present theory, albeit its improvement over the HBChPT, has the limitation
yet to go over to the medium of about 1.3 times of normal matter density due to
the absence of the intrinsic density dependence of the coupling constants. We
discuss how we overcome this limitation in terms of the renormalization method.
