To provide a container for a grain hopper in a grain-carrying vehicle excellent in operability and handleability in which a stopper for supporting the grain hopper in the usual posture is mounted to a caster to facilitate the rotation for converting the posture of the grain hopper to the containing one.

A grain hopper H which can be freely mounted or demounted to/from the loading platform of a truck is rotatably supported on a shaft with a rotation shaft line extending along the longitudinal or transverse line to the caster W2. Simultaneously, the center of the gravity of the grain hopper H is deviated to one side to the rotation shaft line and supported to the caster W2 in such a balance that it tends to rotate toward the heavy side. Further, stoppers S1 and S2 and the caster W2 are mounted to support the hopper H in its usual posture by regulating the rotation end.