[Show abstract][Hide abstract] ABSTRACT: 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.