  Among the extrasolar planetary systems about 30 are located in a stellar
binary orbiting one of the stars, preferably the more massive primary. The
dynamical influence of the second companion alters firstly the orbital elements
of the forming protoplanet directly and secondly the structure of the disk from
which the planet formed which in turn will modify the planet's evolution. We
present detailed analysis of these effects and present new hydrodynamical
simulations of the evolution of protoplanets embedded in circumstellar disks in
the presence of a companion star, and compare our results to the system
$\gamma$ Cep. To analyse the early formation of planetary embryos, we follow
the evolution of a swarm of planetesimals embedded in a circumstellar disk.
Finally, we study the evolution of planets embedded in circumbinary disks.
