To provide a usage of a pouch container for a hydraulic composition material, which simply performs execution hardly performed by an iron or a spatula by performing the stirring and mixing work and filling work of mortar in the same container to suppress the occurrence of dust almost to zero.

The usage of pouch container for a hydraulic composition material is characterized in that the pouch container, which is equipped with an accommodation part for separately accommodating powder and water both of which constitute the hydraulic composition material and a partition device for holding the pouch container from the front and rear sides thereof to mutually demarcate the accommodation parts, is set so that the accommodation part 2 accommodating the powder is positioned so as to become an upper part while the accommodation part 3 accommodating water is positioned so as to become a lower part, and in that the partition device for mutually demarcating the accommodation parts comes off by pulling the upper end of the accommodation part 2 and the lower end of the accommodation part 3 and the powder in the accommodation part 2 falls in the water in the accommodation part 3 to be preliminarily mixed with the water. The hydraulic composition material is prepared by further deforming the pouch container from the outside to mix the powder with water.