An automatic locking guitar holding rack comprises a brace arm, a first movable lock device and a second movable lock device separated from the first movable lock device. The first movable lock device has a first movement portion located on the first holding section, and the second movable lock device has a second movement portion on the second holding section. The first and second movement portions are separated. The first movable lock device is depressible by the head of a guitar to move a first actuation member in a first compression displacement to drive a first confining member to proceed a first swivel displacement. The second movable lock device is depressible by the head of the guitar to move a second actuation member in a second compression displacement to drive a second confining member to proceed a second swivel displacement.