  Orbital-free density functional theory as an extension of traditional
Thomas-Fermi theory has attracted a lot of interest in the past decade because
of developments in both more accurate kinetic energy functionals and highly
efficient numerical numerical methodology. In this paper, we developed a new
conjugate-gradient method for the numerical solution of spin-dependent extended
Thomas-Fermi equation by incorporating techniques previously used in Kohn-Sham
calculations. The key ingredient of the new method is an approximate
line-search scheme and a collective treatment of two spin densities in the case
of spin-dependent ETF problem. Test calculations for a quartic two-dimensional
quantum dot system and a three-dimensional sodium cluster,$\mr{Na}_{216}$, with
a local pseudopotential demonstrate that the method is accurate and efficient.
