A spine fixing apparatus, comprising: a plate fixable to a spine, the plate including a plurality of screw holes being spaced apart from each other at predetermined intervals on the plate and formed through the plate;screws insertable into the spine by being couplable to the plate; a rotation member for rotary motion at a predetermined location between a pair of screw holes provided at opposite sides of the rotation member; and sliding members provided at opposite sides of the rotation member for rectilinear motion, each of the sliding members being disposed between the rotation member and each of the screw holes, the spine fixing apparatus being capable of switching between a lock mode and an unlock mode, the plate including an accommodation space formed by being depressed in a moving direction of the sliding members for accommodating the sliding members and the rotation member such that the respective sliding members rectilinearly move within the accommodation space, and switch between the lock mode and the unlock mode, the accommodation space including a first guide rail for guiding a motion of the respective sliding member by being configured to have a sliding surface, a side wall of the respective sliding member coming into contact with the sliding surface of the first guide rail, and including a first sliding surface being in a shape complementary to a shape of the first guide rail, the first guide rail pressing the first sliding surface so as to prevent the respective sliding member from being separated from the accommodation space, the rotation member rotatably moving at the center of the accommodation spacer, characterized in that the accommodation space includes a locking corner formed by being bent from a first end of the first guide rail to an inside of the accommodation space, and a second guide rail extending from the locking corner toward the screw holes in parallel with first guide rail; and the side wall of the respective sliding member includes a side ridge formed by being bent from a first end of the first sliding surface to an inside of the respective sliding member, and a second sliding surface extending from an end of the side ridge in parallel with the first sliding surface; and the rotation member and each sliding member have a symmetric structure, wherein the rotation member rotates to be in parallel with the moving direction of the sliding members so that the side ridge is locked to the locking corner so as to limit the rectilinear motion of the respective sliding member within the accommodation space and the second guide rail presses the second sliding surface so as to prevent the respective sliding member from being separated from the accommodation space. a plate fixable to a spine, the plate including a plurality of screw holes being spaced apart from each other at predetermined intervals on the plate and formed through the plate;screws insertable into the spine by being couplable to the plate; a rotation member for rotary motion at a predetermined location between a pair of screw holes provided at opposite sides of the rotation member; and sliding members provided at opposite sides of the rotation member for rectilinear motion, each of the sliding members being disposed between the rotation member and each of the screw holes, the spine fixing apparatus being capable of switching between a lock mode and an unlock mode, the plate including an accommodation space formed by being depressed in a moving direction of the sliding members for accommodating the sliding members and the rotation member such that the respective sliding members rectilinearly move within the accommodation space, and switch between the lock mode and the unlock mode, the accommodation space including a first guide rail for guiding a motion of the respective sliding member by being configured to have a sliding surface, a side wall of the respective sliding member coming into contact with the sliding surface of the first guide rail, and including a first sliding surface being in a shape complementary to a shape of the first guide rail, the first guide rail pressing the first sliding surface so as to prevent the respective sliding member from being separated from the accommodation space, the rotation member rotatably moving at the center of the accommodation spacer, characterized in that the accommodation space includes a locking corner formed by being bent from a first end of the first guide rail to an inside of the accommodation space, and a second guide rail extending from the locking corner toward the screw holes in parallel with first guide rail; and the side wall of the respective sliding member includes a side ridge formed by being bent from a first end of the first sliding surface to an inside of the respective sliding member, and a second sliding surface extending from an end of the side ridge in parallel with the first sliding surface; and the rotation member and each sliding member have a symmetric structure, wherein the rotation member rotates to be in parallel with the moving direction of the sliding members so that the side ridge is locked to the locking corner so as to limit the rectilinear motion of the respective sliding member within the accommodation space and the second guide rail presses the second sliding surface so as to prevent the respective sliding member from being separated from the accommodation space.