An extensible pedicle screw coupling device for holding a spinal rod in the head of a pedicle screw is disclosed. The device is extensible so as to fasten to the rod stably while maintaining fixing power if there is a gap between the vertebra and the rod. The device comprises pedicle screws that are inserted into the vertebrae, and a coupler in which the pedicle screw inserted into the vertebra and a head of the pedicle screw are connected, and the rod is housed therein, and fixes the rod by screw fastening the retainer to a thread formed on the top, and an extending means that can adjust the length so as to correspond to the distance between rod and vertebra is installed on the pedicle screw and the coupler.
