Disclosed is a device for tightly gripping on the spinous process, installed between two spinous processes, with a horizontal hole through the main body, and two arc-shaped side plates connecting onto two ends of the main body, each plate having a through hole, and fastening on the spinous process, and a centrally placed item passing through a horizontal hole of the main body thereby connecting the main body and the two plates, and firmly fastened by a single or plurality of fastening items on one or two sides of the centrally placed item. Furthermore, the centrally placed item having at least one fixed hole section, and when the fastening items move toward the main body and tighten, the two plates change shape, putting pressure on the upper and lower gripping section of the two plates, this upper and lower gripping section therefore more firmly gripping on the spinous process.
