I receive cash $15,000 to $30,000 a year as gift from my foreign friend, should I file tax on that? Is there any limits each year?

No, gifts are not taxable to the recipient and do not have to be reported on your tax return.

Thanks for your answer. But should I show any papers to IRS that this is cash gift, not income?

You can record it as nontaxable income in the Sales Tax deduction section if you itemize.

I see, thanks! But I don't have to add it on the sales tax deduction section, right?

No you do not have to

Great, thank you very much. Another questions, because this is large amount cash received in once, when I save them in my bank, should I notice them that this is gift? As usually save over $10,000, they will report. I just wanted to make sure i will not get into any troubles.

Great, thank you very much. Another questions, because this is large amount cash received in once, when I save them in my bank, should I notice them that this is gift? As usually save over $10,000, they will report. I just wanted to make sure i will not get into any troubles.

Yes, to be completely safe, you could ask the person who gave it to you to write something out at the time you receive it (like the cards I used to get in college from my parents!) or memo on check deposited-  otherwise, as you said note it on your bank statement

That's great idea. At least I would add the note on my bank statement. Thank you so much for your help!