Abstract: A toilet seat lifting device comprised of a box fastened to the toilet bowl of a toilet at the top near the back, two sliding racks made to slide in two bevel guide channels on the bottom of the box at two opposite sides, a transmission assembly driven by a slow speed motor to move the sliding racks up and down along the guide channels, and a toilet seat covered on a toilet bowl and having a rear end pivotably connected between the sliding racks, whereby the toilet seat is lifted and lowered between a horizontal position and a bevel position to help the user sit on the toilet seat or stand up from the toilet seat as the slow speed motor is controlled to move the sliding racks forward and backward alternatively.