  More precise extractions on the two important CKM matrix elements $|V_{cb}|$
and $|V_{ub}|$ are presented up to $1/m_Q^2$ corrections based on the complete
heavy quark effective field theory (HQEFT) of QCD. The HQEFT as a large
component QCD provides us a complete theoretical framework for correctly and
systematically evaluating the subleading and higher order contributions in
$1/m_Q$ expansion of heavy quarks. A global analysis on charmless B decays is
made based on the isospin and SU(3) flavor symmetry. An isospin relation is
found to be very useful for studying SU(3) symmetry breaking effects of strong
phases and exploring new type of electroweak penguin effects. The direct CP
violation in charmless B decays is predicted and its precise measurement is
helpful either for testing SU(3) symmetry breaking effects of strong phases or
for probing new physics beyond standard model.
