Congo's president is running in the central African nation's November elections.
President Joseph Kabila filed on Sunday. His sister Jaynet Kabila says his re-election will allow him to continue Congo's reconstruction.
Kabila took office in 2001 after his father's assassination. He was elected in 2006 in the country's first democratic election in 40 years.
He has pushed through a series of constitutional changes to strengthen his powers and replace the two-round voting system with one winner-takes-all round.
Kabila's biggest challenger is veteran politician Etienne Tshisekedi.
His main opponent in 2006, former Vice President Jean-Pierre Bemba, is not running. He awaits an International Criminal Court trial on charges of murder, rape and pillage in neighboring Central African Republic.