An air discharge valve for a bedclothes compressing-and-storing bag includes a lower main body having an air passage and a packing-receiving groove. An upper body is coupled to the lower main body to define an internal space. The upper body has a plurality of air discharge holes and a central guide opening. A valve body positioned in the internal space and slidably inserted into the guide opening of the upper body for movement between an open position and a closed position. A packing is fitted to the packing-receiving groove of the lower main body, the packing provided with an outer flange portion and an inner flange portion. A top cover is fitted to the valve body for movement together with the valve body, the top cover shaped and sized to close off the air discharge holes of the upper body when the valve body is in the closed position.