According to one embodiment, an amine-containing water concentration system includes an osmotic pressure generator and a carbon dioxide introducing unit. The osmotic pressure generator includes a treatment vessel, a first chamber to which the water to be treated is supplied, a second chamber capable of storing a working medium, and a semipermeable membrane that partitions the first chamber and the second chamber, which are located in the treatment vessel. The carbon dioxide introducing unit is capable of introducing carbon dioxide into the water to be treated.