I am a U.S. citizen.
My brother in korea wants to give a property in the U.S. to me as a gift.
In this case is he required to file a gift tax return and pay gift tax?
Is he also entitled for the gift tax credit even if he is a foreign person?

Only US citizens need file a gift tax form. So assuming your brother is not a US citizen, then no - he does not need to file or pay gift taxes, even though the property is located in the US. See "who must file" for form 709 (the Gift Tax Form) here: Instructions for Form 709 (2010)

And since the gift tax credit goes against estate taxes, that doesn't apply here either.

Yes, he has to file and pay tax if the gift exceeds $13,000. See page 3 of instructions to Form 709 (titled "Nonresident Aliens").

I stand corrected - thanks IntlTax. I'm afraid I was fooled by page 1 of the instructions which mentions only US citizens and residents under "who must file." But indeed on page 3 it specifically addresses nonresident aliens who give tangible property located in the US. And as I read the instructions further, it appears that non-resident aliens are NOT entitled to the lifetime gift tax exclusion, so gift taxes will indeed be due if the property is valued at more than the annual exclusion of $13K. Ouch!

Nonresident aliens are not qualified for the lifetime exclusion. I believe that resident aliens do qualify.