  In this article, we calculate the form factors and the coupling constant of
the $g_{B^{\ast}_{s1}B^{\ast} K}$ vertex in the framework of the three-point
QCD sum rules. Three point correlation functions responsible for the vertex are
evaluated by considering both $B^{\ast}$ and $K$ mesons as off-shell states.
The form factors obtained are different if the $B^{\ast}$ or the $K$ meson is
off-shell but give the same coupling constant.
