A dental powder/liquid material-containing preparation accommodation bag, which suppresses entrainment of air in mixing a powder material and a liquid material for dispensing, is provided. A powder material 8 is accommodated in a powder material accommodation chamber 3 of a bag body 2, while a liquid material 9 dissolving the powder material 8 and changing into a pasty form in cooperation with the powder material 8 is accommodated in a liquid material accommodation chamber 4 partitioned from the powder material accommodation chamber 3 by a weakened section 7. The weakened section 7 is ruptured by applying a pressing force to the bag body 2. As a result, the powder material accommodation chamber 3 and the liquid material accommodation chamber 4 communicate, to feed the liquid material accommodated in the liquid material accommodation chamber 4 into the powder material accommodation chamber 3. Then, the powder material 8 and the liquid material 9 changing into the pasty form are pressed within the powder material accommodation chamber 3 from the surfaces of the bag body 2 for dispensing.