Friends of Flyer Talk give me many great suggestions. Now:
1. I use Citi Dividend card--all supermarket, gas and drugstore 5% cash back
2. I use PremierPass Elite Level--All air tickets 1 mile=1 point+$1=1 point
3. I use American Express Starwood--High value points and oversea transfer
4. I use Diners Club--I don't know.
5. I use ICBC Platinum card--Free Priority Pass

I want to know whether I should apply or convert this card:
Citi mtvU card of student--all restaurant (include fast food), bookstore $1=5 points GPA4.0=2000 Because my friends told me this is a valuable card for restaurant.