Adjustment of status must to become a permanent resident in US.
Adjustment of Status is the process for the spouses of US citizens or lawful permanent residents who are already in the United States. A person who is in the United States on some other status, married to a US citizen after they entered the United States as a visitor, worker or a student, may remain in the United States while their spousal petition is in process. The application process involves filing Form I-485 for Adjustment of Status along with the application for alien relative, Form I-130.
http://www.uscitizenship.info/greencard/Adjustment-of-Status-Form-I-485.jsp