An optical fiber adapter according to the present disclosure includes a main body, two inner housings, a cover plate and an elastic shutter member. The main body has an axial accommodation room defined by a first wall, a second wall, a third wall and a fourth wall, wherein the first wall faces the third wall and connects with the second and fourth walls. The accommodation room has a first opening and a second opening opposing to the first opening. An access opening is provided on the first wall for the inner housings to place within the accommodation room. The cover plate is positioned to cover the access opening on the first wall. The shutter member includes a fixing portion, at least one first hook, a shutter plate and a connecting portion. The fixing portion is positioned on the cover plate and within the accommodation room. The first hook is provided at the fixing portion for the fixing portion to be fixed on the cover plate. The connecting portion connects the fixing portion with the shutter plate. The shutter plate extends from the connecting portion and is positioned within the accommodation room.