To provide an automobile door lock for forming a motor-driven theft- prevention device so that an inside locking lever performs idling motion and an outside locking lever acts.

An automobile door lock is provided with a theft prevention device. A center locking lever 8, an outside locking lever 7 and a connection lever 13 are rockably pivoted on a pivot shaft. A theft prevention driven element 17 and a theft prevention disc 18 are rotatably pivoted on a rotation shaft parallel with the pivot shaft. A theft prevention device is operated through a center locking drive device operated on the center-locking lever. In addition, a theft prevention drive device operated on the theft prevention driven element is provided. When the theft prevention device is being operated, an inside locking lever performs idling motion and the connection lever is held unmovable. The connection lever 13 forms a connection member between a rotation latch 1 provided with a locking claw 2 and a locking mechanism or the theft prevention device.