  Some selected topics in flavour changing neutral current processes in $B$
decays are discussed in the context of the Standard Model. The emphasis here is
on the determination of the CKM matrix elements from the ongoing and
forthcoming experiments. The topics discussed include: (i) CKM-allowed
radiative decays $B \to X_s + \gamma$, (ii) CKM-suppressed radiative decays $B
\to X_d + \gamma$, $B^\pm \to \rho^\pm + \gamma$ and $B^0 \to (\rho^0,\omega) +
\gamma$, (iii) $B^0 - \bar{B^0}$-mixings, and (iv) the Fleischer-Mannel bound
in $B \to K\pi$ decays.
