  We explore the anomalous right-handed $\bar{t}sW$ and $\bar{t}bW$ couplings
using $ B \to X_s \gamma$ and $B \to X_s l^+ l^-$ decays induced by the
flavour-changing penguin diagrams. The anomalous $\bar{t}sW$ coupling can yield
10% enhancement of the $B \to X_s l^+ l^-$ decay rate under the constraint from
the present $B \to X_s \gamma$ data, while it does not affect the
forward-backward asymmetry of the charged lepton. The allowed region for
anomalous $\bar{t}bW$ coupling by the $ B \to X_s \gamma$ constraint is
two-fold, the small value region and the large value region. Though the effect
of the small anomalous coupling on the $B \to X_s l^+ l^-$ branching ratio is
very little, it can yield a substantial chanhge for the forward-backward
asymmetry.
