The present invention relates to a line post insulator. A screw bar (44) of a tightening unit (40) is assembled in a screw pipe (20) inserted and fixed in a head portion (11) of a core bar (10). A power line (500) horizontally penetrating the head portion (11) and the screw pipe (20) is fixed by a power line pressing part (30) having a semispherical protrusion (32) coming in contact with an arc-shaped groove (45) formed on a lower surface of the screw bar (44) of the tightening unit (40). A fixing pin (50) which prevents the head portion (11) from loosening and escaping from the tightening unit (40) is inserted and fixed in a hole (42) of the tightening unit (40) and a hole (13) of the head portion (11) to resolve numerous problems caused by using a conventional binder wire (a steel wire coated with aluminum) for fixing a line post insulator and a power line.
