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) (http://www.irs.gov/instructions/i709/ch01.html#d0e242)

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.