  The purpose of this research is to study the upper critical field (Hc2) of
two-band superconductors by two-band Ginzburg - Landau approach. The analytical
formula of Hc2 included anisotropy of order parameter and anisotropy of
effective-mass are found . The parameters of the upper critical field in
ab-plane and c-axis can be found by fitting to the experimental data . Finally,
we can find the ratio of upper critical field that temperature dependent in the
range of experimental result .
