Vehicle on-board article theft warning system

A vehicle on-board article theft warning system includes detection means for detecting on-board article-specific ID information transmitted from IC chips attached to on-board articles, ID information storing means for storing as initial ID information the article-specific ID information detected by the detection means when a theft detection mode is activated, discrimination means responsive to activation of the theft detection mode for comparing detected ID information consisting of on-board article-specific ID information detected by the detection means with the initial ID information and discriminating whether or not there exists missing ID information defined as ID information contained in the initial ID information but not contained in the detected ID information, and warning means responsive to a discrimination that missing ID information exists for determining that theft of an article corresponding to the missing ID information occurred and issuing a prescribed warning.