  The recently observed possible antimagnetic rotation band in $^{101}$Pd is
investigated by the cranked shell model with pairing correlations treated by a
particle-number conserving method, in which the blocking effects are taken into
account exactly. The experimental moments of inertia and reduced $B(E2)$
transition probabilities and their variations with the rotational frequency
$\omega$ are well reproduced. By analyzing the $\omega$-dependence of the
occupation probability of each cranked Nilsson orbital near the Fermi surface
and the contributions of valence orbitals in each major shell to the total
angular momentum alignment, the upbending mechanism of $\nu h_{11/2}$ in
$^{101}$Pd is understood clearly. The proton angular momentum alignment and its
influence on the two-shears-like mechanism are also discussed.
