To provide an inter-vehicle distance automatic variable system and method in which it is determined whether a road is in a dry state or in a state wet with rain or snow, and a distance between own vehicle and a preceding vehicle is automatically varied according to the state of the road.

The inter-vehicle distance automatic variable system includes: a camera for capturing a road in front of the own vehicle; and a control section which determines the state of the road by utilizing standard image data obtained by predetermined image processing of original image data captured with the camera, then controls an inter-vehicle distance according to the determination result. In case that a streak of rainwater or a white component is detected from the standard image data, the control section determines that the road is in a wet state and sets an inter-vehicle distance in the wet state longer than an inter-vehicle distance in the dry state.