I am a student on F-1 visa in the US. I received $600 honorarium to attend a summer school. I used this money to cover my travel expenses. I have not receoved 1099-misc (or any other) form. Should I report this as an income in my 1040NR-EZ? If so under what category? Since I used it for my travel expenses, should it be still taxed?

Even if you do not get a Form 1099-MISC, it IS still taxable, and can be reported on Schedule C with Form 1040NR. You can deduct your travel costs on the Schedule C, making it a wash.

Thanks for your prompt response. I used to file 1040NR-EZ before. Should I file 1040NR because of the honorarium?
Can I use Schedule C-EZ instead of Schedule C?

I recommend you use Form 1040NR and Schedule C (not C-EZ).