  In this paper, we employ a continuous Ginzburg-Landau model to study the
behaviors of the parallel upper critical field of an intrinsically-layered
superconductor. Near $T_c$ where the order parameter is nearly homogeneous, the
parallel upper critical field is found to vary as $(1-T/T_c)^{1/2}$. With a
well-localized order parameter, the same field temperature dependence holds
over the whole temperature range. The profile of the order parameter at the
parallel upper critical field may be of a Gaussian type, which is consistent
with the usual linear Ginzburg-Landau theory. In addition, the influences of
the unit cell dimension and the average effective masses on the parallel upper
critical field and the associated order parameter are also addressed.
