@mengtaizhang , agreeing with my colleague @DoninGA , what your post does not clarify :
(a) Are you a US person i.e. GreenCard ? Because if that is so , then you still have to file a US 1040 return recognizing your world income.
(b) the answer by my colleague assumes that you are NRA ( Non-Resident Alien) with US source income. Yes , you have to file a 1040-NR recognizing ONLY US sourced income. To do this though you still need a Tax ID -- SSN or ITIN. Do you have that ?
(c) your post implies that you were resident in the USA ( and that is how you have US Bank earnings -- interest ? ). How long were you here and with which visa ? Did you inform the IRS and Immigration that you have left the country ? There may be Exit Tax considerations depending on how long you were a resident . (d) Which country are you a resident of now ? Are you also a citizen of that country ? There may be treaty considerations.
