In an e-mail to supporters, Christie said a formal announcement will come in the first week in February.
The filing allows Christie to start raising money for the 2009 race.
The 46-year-old Republican with a reputation as a corruption-busting prosecutor has been flirting with a gubernatorial bid since resigning as U.S. Attorney Dec. 1.
Gov. Jon S. Corzine plans to seek re-election.
The e-mail was first reported by The Star-Ledger of Newark on its Web site.