  In this paper the effect of the magnetic field on the form of the equation of
state and helium white dwarfs structure are discussed. The influence of the
temperature and magnetic field on white dwarfs parameters have been
investigated. The mass-radius relations for different parameters were obtained.
The occurrence of unstable branches in the mass-radius relation are presented
for the temperature equals T=3 10^8 K and for different values of the strength
of magnetic field. Theoretical model of the star with two Landau levels is
obtained.
