An apparatus for adjusting a seat height of a vehicle, comprising: a height adjusting lever engaged in a gear tooth structure with a height adjusting pivot and changing an engaged structure of the gear tooth with the aid of upward and downward rotations; a height adjusting cable inserted in a cable insertion groove formed at an inner side surface of the height adjusting lever and rotating along a cable guide with the aid of the upward and downward rotations of the height adjusting lever; and a rotor connected with the height adjusting cable for thereby selectively pressurizing an air injection pin or an air discharge pin of a control valve depending on the rotation direction of the height adjusting cable, and adjusting an amount of air in an interior of an air spring which is connected with the control valve and adjusts the height of the seat, wherein the rotor comprises: an arm rod pushed or pulled by the height adjusting cable depending on the rotation of the height adjusting lever and rotated by a pushing or pulling operation of the height adjusting cable; and a push rod engaged with a rotary shaft of the arm rod and pressurizing respectively the air injection pin and the air discharge pin of the control valve depending on the rotation of the arm rod, wherein the push rod comprises: an upper push rod pressurizing the air injection pin provided in an upper side of the control valve depending on a clockwise rotation of the arm rod by means of the pulling operation of the height adjusting cable; and a lower push rod pressurizing the air discharge pin provided in an lower side of the control valve depending on a counterclockwise rotation of the arm rod by means of the pushing operation of the height adjusting cable, and wherein the upper push rod and the lower push rod are respectively engaged with the rotary shaft of the arm rod, wherein the upper push rod and the lower push rod are connected by way of a push rod spring, and the push rod spring receives a rotational force of the arm rod, so the upper push rod pressurizes the air injection pin, and the lower push rod pressurizes the air discharge pin. a height adjusting lever engaged in a gear tooth structure with a height adjusting pivot and changing an engaged structure of the gear tooth with the aid of upward and downward rotations; a height adjusting cable inserted in a cable insertion groove formed at an inner side surface of the height adjusting lever and rotating along a cable guide with the aid of the upward and downward rotations of the height adjusting lever; and a rotor connected with the height adjusting cable for thereby selectively pressurizing an air injection pin or an air discharge pin of a control valve depending on the rotation direction of the height adjusting cable, and adjusting an amount of air in an interior of an air spring which is connected with the control valve and adjusts the height of the seat, wherein the rotor comprises: an arm rod pushed or pulled by the height adjusting cable depending on the rotation of the height adjusting lever and rotated by a pushing or pulling operation of the height adjusting cable; and a push rod engaged with a rotary shaft of the arm rod and pressurizing respectively the air injection pin and the air discharge pin of the control valve depending on the rotation of the arm rod, an arm rod pushed or pulled by the height adjusting cable depending on the rotation of the height adjusting lever and rotated by a pushing or pulling operation of the height adjusting cable; and a push rod engaged with a rotary shaft of the arm rod and pressurizing respectively the air injection pin and the air discharge pin of the control valve depending on the rotation of the arm rod, wherein the push rod comprises: an upper push rod pressurizing the air injection pin provided in an upper side of the control valve depending on a clockwise rotation of the arm rod by means of the pulling operation of the height adjusting cable; and a lower push rod pressurizing the air discharge pin provided in an lower side of the control valve depending on a counterclockwise rotation of the arm rod by means of the pushing operation of the height adjusting cable, and wherein the upper push rod and the lower push rod are respectively engaged with the rotary shaft of the arm rod, an upper push rod pressurizing the air injection pin provided in an upper side of the control valve depending on a clockwise rotation of the arm rod by means of the pulling operation of the height adjusting cable; and a lower push rod pressurizing the air discharge pin provided in an lower side of the control valve depending on a counterclockwise rotation of the arm rod by means of the pushing operation of the height adjusting cable, and wherein the upper push rod and the lower push rod are respectively engaged with the rotary shaft of the arm rod, wherein the upper push rod and the lower push rod are connected by way of a push rod spring, and the push rod spring receives a rotational force of the arm rod, so the upper push rod pressurizes the air injection pin, and the lower push rod pressurizes the air discharge pin.