  Due to the highly degeneracy of electrons in white dwarf stars, we expect
that the relativistic effects play very important role in these stars. In the
present article, we study the properties of the condensed matter in white
dwarfs using Newtonian and relativistic polytropic fluid sphere. Two polytropic
indices (namely n=3 and n=1.5) are proposed to investigate the physical
characteristics of the models. We solve the Lane-Emden equations numerically..
The results show that the relativistic effect is small in white dwarf stars.
