  Theory of weak localization is developed for two-dimensional holes in
semiconductor heterostructures. Ballistic regime of weak localization where the
backscattering occurs from few impurities is studied with account for
anisotropic momentum scattering of holes. The transition from weak localization
to anti-localization is demonstrated for long dephasing times. For stronger
dephasing the conductivity correction is negative at all hole densities due to
non-monotonous dependence of the spin relaxation time on the hole wavevector.
The anomalous temperature dependent correction to the conductivity is
calculated. We show that the temperature dependence of the conductivity is
non-monotonous at moderate hole densities.
