How do you transfer Pokemon in Pokemon Emerald to Diamond?

Answer 1

You need to see all the Sinnoh Pokemon, go and show the Prof in Sandgem Town your Pokedex, and he will tell you about Pal Park.

Save your game and turn your DS off. Then slot your Pokemon Emerald Game Cartridge into the bottom of the DS and turn it on. Go on Pokemon Diamond/Pearl, and this time on the title screen it will say: Migrate From Emerald. Click on it and you can choose any Pokemon from your PC in Emerald and they will later be in the Pal Park. YOU CANNOT GET YOUR POKEMON BACK ONCE TRANSFERED TO DIAMOND/PEARL.

Once you've picked your Pokemon, continue your Diamond/Pearl game and surf off the beach in Sandgem Town until you hit an island. Go through the grass and you will be at a place called Pal Park. The man in the entrance once you have entered the building will tell you about Pal Park, then you can enter, and the 7 Pokemon you chose from your Emerald PC will be available to catch in the wild.

The Pal Park balls are just like Master Balls so you will always catch the Pokemon. You have now migrated your Pokemon from Emerald to Diamond. You must catch all 7 of the migrated Pokemon before leaving the Pal Park. They will each be in different habitats. Once you have caught all 7, they will be in your PC.

Hope This Helped