This is a list of the Pokemon from the Unova region in Pokemon Black & White. In a similar fashion to the Hoenn games, in Black & White the native Pokedex only contains the 156 new Pokemon from Unova. You can later obtain the National Dex which includes the other 493 Pokemon.
One difference to other games in the inclusion of a legendary Pokemon with Pokedex number #000: Victini. It is available quite early in the game through Mystery Gift on Nintendo WFC.
We also have a list of the Pokemon from Black & White, with their stats. There you can sort the table to compare Pokemon and decide your team! See also the Black 2 & White 2 pokedex for the upcoming games.