I am about to file for I-864, How many paystub do I need to proof my current employment? Thank you.

Yes, with translation.

3 pay stubs along with letter of job verification issued by your employer.

I suggest you submit all of your paystubs for the last 6 months, if it's possible to go back that far.

You should also include a letter from your employer indicating your position, length of employment, salary and prospect for continued employment.

If you are filing for adjustment of status, that is, if your green card interview will take place in the US, you only need file a copy of your current tax return with the I-864, including W-2 forms and other attachments, as proof you meet the financial requirements. When they schedule the final interview they usually ask you to bring paystubs for the preceding two months and a job letter from your current employer. If you are a co-sponsor and not the petitioner, you will also need to include proof you are a US citizen or a green card holder. If you are consular processing - that is, if your interview will take place overseas, once the NVC takes over your case you will receive instructions as to what you need to file with your I-864. As usual, the best thing to do in these cases is talk to an attorney before you file anything.