  We determine the chiral corrections to the matrix elements of the Delta B=0
four-quark operators which are relevant to the studies of the ratios of
lifetimes of heavy-light mesons as well as to the power corrections to the
inclusive semileptonic heavy-to-light decays. The chiral logarithmic
corrections computed here can be combined with the forthcoming estimates of the
corresponding matrix elements on the lattice to provide the reliable physics
result of the well known bag-parameters B_(1,2) and epsilon_(1,2).
