  We have performed a variational Monte Carlo simulation to study the ground
state of a two-dimensional Hubbard model on a square lattice in the strong
coupling region. The energy gain of possible inhomogeneous electron states are
computed as a function of $U$ when the hole density $\epsilon=1/8$ and next
nearest-neighbor hopping $t'/t=-0.30$. The bond-centered ferromagnetic diagonal
stripe state is stabilized in the strong coupling region ($U/t\geq$16), which
is due to the gain of both kinetic energy and on-site Coulomb interaction
energy due to the holon moving over the ferromagnetic domain and the gain of
kinetic-exchange-interaction energy at the antiferromagnetic domain wall.
