请参考 1040 NR EZ Instructions
Taxable Income Line 3—Wages, salaries, tips, etc.
Enter the total of your effectively connected wages, salaries, tips, etc. Only U.S. source income is included on line 3 as effectively connected wages. For most people, the amount to enter on this line should be shown in box 1 of their Form(s) W-2. Do not include on line 3 amounts exempted under a tax treaty. Instead, include these amounts on line 6 and complete item J of Schedule OI on page 2 of Form 1040NR-EZ