A parking operation aiding system includes a display for displaying parking-aiding information including a target parking position and a vehicle position. The system also includes a locus calculating means for calculating an expected movement locus for a subject vehicle in accordance with a distance of movement of the vehicle and a steering angle, an interference determining means for determining whether the expected movement locus will interfere with the target parking position, and an information determining means for determining subsequent parking operation aiding information based on the presence or absence the interference.