One of my friend wants to buy a house in USA. He is on the process of green card,, filed I485 and the case is Pending. He has an average income job and a sound bank balance.Is it possible for him to buy a house?

He asked me for advice but i am blank about that field. Is there anyone who can give him good advice?

Of course he can. As long has he can show a stable income, he can easily get loan. Buying a home has nothing to do with status of getting greencard.

And of course, a good credit score...

There used to be a time you could be in F1, J1 or some legal status and the bank would give you loan to buy a house. But now that the economy is hurt, it depends on the bank. About 6 months ago, one of my friends wanted to buy a house with a H1B visa (his greencard was already in process) but the bank did not agree. They told him that green card was required. Different banks might have different rule. Things might have changed in the past 6 months. The best way is to go talk to a few banks first instead of just relying on our suggestions. I believe Credit Unions might be more flexible than the big name banks..Let us know how it goes. Good luck.