A fire hydrant box accommodates a hand held firefighting spray gun, a water inlet pipe with a rotary connector and a connection unit. A positioning member capable of bearing gravity is installed on the sidewall inside the box. A rotary member is movably connected with the positioning member, from which two supporting members extend to engage and support a rotary base of a firefighting hose assembly. The rotary base includes a rolling mechanism used to roll the fire hose thereon. Two rolling disks are provided to two sides of the rolling mechanism. One rolling disk is provided with a handle to roll and release the fire hose, and the other rolling disk is connected to the water inlet pipe. The connection unit can be easily rotated out of the accommodating space in order for the fireman to easily access the fire hose and the firefighting spray gun.