Things You'll Need
Instructions
Turn on your DS with the DS Pokemon title you want to migrate characters to. Also turn on the GBA game you want to migrate from in the GBA slot. Because you need the GBA slot, this will only work with an original DS or DS Lite. DSi, XL, and 3DS do not have a slot for a GBA game.
Make sure you have beaten the Elite Four in your DS Pokemon title and obtained the National Pokedex. This will unlock the Pal Park, which is found on Route 221 in Pearl, Diamond and Platinum, and in Fuchsia City in Heart Gold or Soul Silver.
Start your DS Pokemon game. On the main menu, you will see "Migrate from (name of GBA game)." Pick this option to access your stored Pokemon from the GBA game.
Pick six Pokemon to migrate. You can only transfer six characters per day in Diamond, Pearl and Platinum, You can transfer multiple groups of six throughout the day in Heart Gold and Soul Silver.
Load your game and talk to the person at the front desk of Pal Park. He will give you special Poke Balls and let you into Pal Park.
Find and capture your transferred Pokemon throughout the park. You have a 100 percent capture rate, so you can't lose your transferred Pokemon. But you must find them in the park. If you can do this quickly, you will get different prizes depending on which game you are playing and how well you did.