In a process for producing a loudspeaker diaphragm, pulp is deposited on a paper-making mold in the presence of vortex stream of water having pulp dispersed therein in a paper-making bath. Pulp is deposited on the paper-making mold while at least the water having pulp dispersed therein is rotated by the vortex stream in the paper-making bath. Consequently, variation of pulp fiber orientation is suppressed, and a loudspeaker diaphragm with high reproducibility and stable quality is produced with a high productivity.