  We analyze the semileptonic $B \to a_1 \ell^+\ell^-$, $\ell=\tau, \mu, e$
transitions in the frame work of the three-point QCD sum rules in the standard
model. These rare decays governed by flavor-changing neutral current transition
of $b \to d$. Considering the quark condensate contributions, the relevant form
factors as well as the branching fractions of these transitions are calculated.
