  We calculate the amplitudes of $b\to s$ transition in extension of the Standard Model with $Wtb$ anomalous couplings. We found that i) there exist the Ward identity violating terms in effective vertix of $b\to s\gamma$. The terms, which come from the tensor parts of $Wtb$ anomalies, and can be canceled exactly by introducing corresponding $Wtb\gamma$ interactions, ii) $Br(B_{s} \to \mu^{+}\mu^{-})$ provides unique information on $\delta v_L$ which is set to zero in top decay experiments, and stringent bounds on $v_R,\ g_L$ by $Br(B\to X_s\gamma)$ are obtained. 
Constraints on $Wtb$ anomalous coupling with $ B\to X_{s}\gamma $ and   $B_{s}\to\mu^{+}\mu^{-}