  The periapsis shift (PS) of spinning test particles in the equatorial plane
of arbitrary stationary and axisymmetric spacetime is studied using the
post-Newtonian method. The result is expressed as a half-integer power series
of $M/p$ where $M$ is the spacetime mass and $p$ is the semilatus rectum. The
coefficients of the series are polynomials of the particle spin, the asymptotic
expansion coefficients of the metric functions and the eccentricity of the
orbit. The particle spin is shown to have a similar effect as the
Lense-Thirring (LT) effect on the PS, and both of them appear from the
$(M/p)^{-3/2}$ order in the PS. The coupling between the spacetime and particle
spins will increase (or decrease) the PS if they are parallel (or
antiparallel). For Jupiter and Saturn rotating around the Sun and exceptionally
designed satellites around Mercury and Moon, the particle spin effect can be
comparable to the LT one in size. The PS in other spacetime studied are not
distinguishable from that in the Kerr spacetime to the $(M/p)^{-3/2}$ order.
