  The observational data from some black hole candidates suggest the importance
of electromagnetic fields in the vicinity of a black hole. Highly magnetized
disk accretion may play an importance rule, and large scale magnetic field may
be formed above the disk surface. Then, we expect that the nature of the black
hole spacetime would be reveiled by magnetic phenomena near the black hole. We
will start to investigate the motion of a charged particle which depends on the
initial parameter setting in the black hole dipole magnetic field. Specially,
we study the spin effects of a rotating black hole on the motion of the charged
particle trapped in magnetic field lines. We make detailed analysis for the
particle's trajectories by using the Poincar\'{e} map method, and show the
chaotic properties that depend on the black hole spin. We find that the
dragging effects of the spacetime by a rotating black hole weaken the chaotic
properties and generate regular trajectories for some sets of initial
parameters, while the chaotic properties dominate on the trajectories for
slowly rotating black hole cases. The dragging effects can generate the fourth
adiabatic invariant on the particle motion approximately.
