Lt Gen Md Abdul Mubeen will take over as the chief of army staff today.
He will succeed Army Chief General Moeen U Ahmed.
The outgoing army chief, who was appointed to this post on July 15, 2005, will go into retirement the same day on completion of his tenure of service.
Lt Gen Mubeen will also be promoted to the rank of general with effect from today.
Sources said the chiefs of naval staff and air staff would decorate Mubeen with the rank badge at a programme in presence of Prime Minister Sheikh Hasina at the office of Armed Forces Division in Dhaka cantonment in the afternoon.
In the first week of this month, President Zillur Rahman appointed Mubeen as the new army chief for three years from June 15, 2009 to June 15, 2012.
Outgoing Army Chief Moeen went to Bangabhaban for paying a farewell call on the president.
Moeen's job tenure was scheduled to expire on June 15, 2008, but in April 2008, the then President Iajuddin Ahmed extended his job for one year.
Moeen was one of the key architects of the 1/11 political changeover during the last caretaker government regime.
He took a leading role in backing the interim government that lasted for two years and culminated with the general elections on December 29, 2008.
The newly appointed army chief hails from Kishoreganj. He was made PSO of the Armed Forces Division from major general rank on June 4, 2008. He was general commanding officer of Jessore and 24th Infantry Division in Chittagong.
Son of Major Baseth and an ex-cadet of Mirzapur Cadet College, Mubeen was commissioned in November, 1977 as an infantry officer from the third Short Course of Bangladesh Military Academy.