  We give a simple method to calculate the semiclassical $D$-brane boundary
states of the bosonic string propagating in an arbitrary curved spacetime in a
perturbative approach in which the metric $g_{AB}$ and the constant
antisymmetric Kalb-Ramond field $b_{AB}$ form the general background which is
treated exactly. As an important particular case, it is shown that at the first
order perturbation theory there are $D$-brane coherent states in the
$d$-dimensional {\em AdS} spacetime if certain conditions are fulfilled by the
boundary projectors.
