Disclosed is a spinal pedicle screw assembly including a spinal pedicle screw cooperating with a spine rod for fixing a spine, which includes: a head-coupling element having an upper and a lower end, a rod-receiving channel opening toward the upper end for receiving the spine rod, female screw threads formed on the inside of the rod-receiving channel, and a connecting bore of a given size extending through the lower end, the connecting bore having an upper end toward the rod-receiving channel and an opposite lower end; a screw rod having an upper and a lower end, a spherical head integrally formed with the upper end thereof for being inserted into the connection bore, and male screw threads formed on the periphery of the screw rod between the spherical head and lower end thereof, the screw rod being fixedly inserted into the pedicle by means of the male screw threads thereof; a tightening screw having a periphery formed with male screw threads for engaging the female screw threads of the rod-receiving channel so as to fix the spine rod in the head-coupling element; and a final fixing screw threadedly engaged by the connecting bore for preventing the spherical head from disconnecting from the head-coupling element.