If a marry to a US citizen and we divorce after some months, what happens to my residency status?

If by some months later, you mean within six months, you would likely not be granted residence status in this country as most immigration offices are taking 6+ months to interview applicants in marriage based cases. Your girlfriend's timing is incorrect also in that an advance parole travel document usually takes approximately 90 days to obtain after application. If you maintain your legal status under F-1, you could have a plausible defense against being removed from the country in the event that your marriage based case does not work out on the theory that you are still legal and not amenable to removal proceedings.Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.