  Lattice matrix elements are briefly reviewed. In the quenched approximation
$f_B$, $B_B$ and $B_K$ are now under good control. Experimental hints for
$f^{\rm expt}_{D_S}> f^{\rm QQCD}_{D_S}$ are noted; precise determination of
$f_{D_S}$ from experiment as well as from the lattice is strongly advocated.
Lattice calculations of the form factor for $B\to\pi\ell\nu$ at relatively
large value of $q^2$ have made good progress and should be useful in
conjunction with precise measurement of the differential spectra expected from
$B$-factories. Recent attempt at $K\to \pi\pi$ using staggered quarks is
briefly discussed; use of non-perturbative renormalization, improved actions
and operators with staggered quarks is emphasized. Due to the good chiral
behavior of domain wall quarks it would be useful to study $K\to \pi\pi$ with
this discretization.
