Abstract: Considering the influence of ion's nonlinear polarization drift on Solitary Kinetic Alfvér Wave (SKAW), the character of the low-frequency dip SKAW in the magnetic plasma is investigated with the two-fluid mode. The derived results indicate that two kinds of dip SKAW both exist in a wide range in magnetosphere (for the pressure parameter β-10^-6-0.1, where β is the ratio of thermal pressure to magnetic pressure, i.e. β = 2μ₀ nT/B₀²). They propagate at Sub- Alfvéric speed or Super-Alfvéric speed. And ion's nonlinear polarization drift has great effect on the SKAW when the value of β is smaller (β-10^-6-10^-4). It can not be neglected. But it has weak effect on the SKAW when the value of β is bigger (β - 0.1). Because of the SKAW having the parallel electric field, the solitary wave is important for the acceleration and energy transmission of charged particles in magnetic plasma. And the SKAW is also put effects on the transverse ion transverse acceleration. The SKAW makes a novel kind of mechanism of energy transmission possible.