Dear researchers,

Is it possible to open a major credit card account (with cashback
rewards), such as Chase, Discover, or Citi Card for someone who is
just arrived in US few weeks and just received her new SSN?
I would like to tell her to try apply one, and see what's the result.
But if she got rejected, will it affect/reduce her credit score??
She needs a credit card soon and wants one with cashback rewards.

Unless she has built a credit history in the United States, I think
it's quite unlikely that she'll be able to get a major credit card.
Perhaps her best bet is a secured card or a debit card that is
attached to a checking account.

Thanks for the comment, Pink. 
Do you know if someone got rejected for applying a credit card, does
it reduce his/her credit score?
In this case, if she gave it a shot then got rejected, is that going
to affect her credit score?....if it doesn't, I'll suggest her to give
it a try.

I am not an expert on this, but it is my understanding that being
rejected for a credit card does have a negative impact on your credit
record.

From a Kiplinger's article:

"Being rejected for a credit card can also hurt your chances of being
accepted for one in the future."

http://www.kiplinger.com/personalfinance/basics/managing/cash/firstcc.htm

Tell your friend to start building a credit history by applying for a
couple of Store charge cards...Saks, Bloomingdales, Target, etc. ....I
recieved my new SS number a few months ago and the strategy appears to
be working. Needless to say, she will need to be assiduous in her
payment history and keep any balances low. Inquiries for new credit DO
show up on your report and may give the impression that you are
applying for more credit to get out of debt. Unfortunately there is no
quick fix...she's going to have to be patient.