Do I need to apply for re entry permit everything I visit USA or one time and will be valid for all?

your residence will be Brazil and therefore you greencard will be voided ,..returning twice a year will not keep it ..you will need to actually have property and all the trappings of living in the US to keep it ..you should return it using form I-407

Your question is interesting and one that we here on Yahoo Answers cannot answer with any degree of certainty since you will remain a PR of the United States until an Immigration Judge rules otherwise. You can *attempt* to live in Brazil and retain your PR status in the U.S but it will probably catch up with you with your frequency of entry verses length of stay. FWIW, you only need to file Form I-131 if you plan to reside outside of the U.S. for more than year. So if you visit the U.S. twice a year, there is no need to file said Form. Make sure you try to keep as many ties as possible to the U.S.-- bank accounts, insurance, etc etc.

Two pretty good answers already. Since you may lose your green card by taking up residency in Brazil, you might consider applying for citizenship. Once you become a citizen, where you live won't affect your status. A US citizen can live anywhere. Apply as quickly as possible. ... Good luck!

If you take up residency in Brazil, your Green Card will be taken away from you. Even with a reentry permit, you will have to show that you did not abandon your U.S. residency. You need to show that you still occupy a house or apartment, have a car in your driveway, insurances . . . basically everything a person who lives in the U.S. would have, even if you are "temporary" in Brazil. You can't keep your Green Card alive by using it like a tourist visa. They have computers now, you know, and everytime they slide your Green Card, your entire travel history comes up. If you need to move to Brazil for a longer time, turn in your Green Card and get yourself a shiny new one when you plan on moving back to the U.S.