  The perturbative QCD (PQCD) approach based on $k_T$ factorization has made a
great achievement for the QCD calculation of the hadronic B decays. Regulating
the endpoint divergence by the transverse momentum of quarks in the
propagators, one can do the perturbation calculation for kinds of diagrams
including the annihilation type diagrams. In this paper, we review the current
status of PQCD factorization calculation of two-body charmless $B\to PP, PV,
VV$ decays up to the next-to-leading order (NLO) QCD corrections. two new power
suppressed terms in decaying amplitudes are also taken into account. By using
the universal input (non-perturbative) parameters, we collected the branching
ratios and ${\bf CP}$ asymmetry parameters for all the charmless two body $B$
decays, calculated in the PQCD approach up to the NLO, including some power
suppressed terms in decaying amplitudes. The results are compared with the ones
from QCD factorization approach, soft-collinear effective theory approach and
the current experimental measurements. For most considered B meson decays, the
PQCD results for branching ratios agree well with other approaches and the
experimental data. The PQCD predictions for the ${\bf CP}$ asymmetry parameters
for many of the decay channels do not agree with other approaches, but have a
better agreement with the experimental data. The longstanding $K \pi $ puzzle
about the pattern of the direct CP asymmetries of the penguin-dominated $B \to
K \pi $ decays can be understood after the inclusion of the NLO contributions
in PQCD. The NLO corrections and power suppressed terms play an important role
in the color suppressed and pure annihilation type $B$ decay modes. These rare
decays are more sensitive to different types of corrections, providing
opportunity to examine the factorization approach with the more precise
experimental measurements.
