A driving assistance system comprising: an inter-vehicle distance detecting unit configured to detect an inter-vehicle distance between a forward vehicle and a subject vehicle; a relative velocity detecting unit configured to detect a relative velocity between the forward vehicle and the subject vehicle; an inter-vehicle distance control unit configured to control the subject vehicle such that the inter-vehicle distance becomes equal to a target inter-vehicle distance, determine that a notification condition is satisfied, when an inter-vehicle distance between a stopped subject vehicle and the forward vehicle becomes equal to or larger than a predetermined first distance and the relative velocity becomes equal to or higher than a predetermined first velocity, or the inter-vehicle distance between the stopped subject vehicle and the forward vehicle becomes equal to or larger than a predetermined second distance, the predetermined second distance being larger than the predetermined first distance, and perform a first notification operation on a driver when the notification condition is satisfied; and a forward vehicle start notifying unit configured to set an inter-vehicle distance in a condition where both of the forward vehicle and the subject vehicle are stopped, as a reference inter-vehicle distance, and perform a second notification operation on the driver, when a difference between the reference inter-vehicle distance and the inter-vehicle distance becomes equal to or larger than a predetermined third distance, characterized in that the forward vehicle start notifying unit is configured not to perform the second notification operation on the driver, at least until after the inter-vehicle distance control unit performs the first notification operation, when the inter-vehicle distance control unit is in an active state. an inter-vehicle distance detecting unit configured to detect an inter-vehicle distance between a forward vehicle and a subject vehicle; a relative velocity detecting unit configured to detect a relative velocity between the forward vehicle and the subject vehicle; an inter-vehicle distance control unit configured to control the subject vehicle such that the inter-vehicle distance becomes equal to a target inter-vehicle distance, determine that a notification condition is satisfied, when an inter-vehicle distance between a stopped subject vehicle and the forward vehicle becomes equal to or larger than a predetermined first distance and the relative velocity becomes equal to or higher than a predetermined first velocity, or the inter-vehicle distance between the stopped subject vehicle and the forward vehicle becomes equal to or larger than a predetermined second distance, the predetermined second distance being larger than the predetermined first distance, and perform a first notification operation on a driver when the notification condition is satisfied; and control the subject vehicle such that the inter-vehicle distance becomes equal to a target inter-vehicle distance, determine that a notification condition is satisfied, when an inter-vehicle distance between a stopped subject vehicle and the forward vehicle becomes equal to or larger than a predetermined first distance and the relative velocity becomes equal to or higher than a predetermined first velocity, or the inter-vehicle distance between the stopped subject vehicle and the forward vehicle becomes equal to or larger than a predetermined second distance, the predetermined second distance being larger than the predetermined first distance, and perform a first notification operation on a driver when the notification condition is satisfied; and a forward vehicle start notifying unit configured to set an inter-vehicle distance in a condition where both of the forward vehicle and the subject vehicle are stopped, as a reference inter-vehicle distance, and perform a second notification operation on the driver, when a difference between the reference inter-vehicle distance and the inter-vehicle distance becomes equal to or larger than a predetermined third distance, characterized in that set an inter-vehicle distance in a condition where both of the forward vehicle and the subject vehicle are stopped, as a reference inter-vehicle distance, and perform a second notification operation on the driver, when a difference between the reference inter-vehicle distance and the inter-vehicle distance becomes equal to or larger than a predetermined third distance, characterized in that the forward vehicle start notifying unit is configured not to perform the second notification operation on the driver, at least until after the inter-vehicle distance control unit performs the first notification operation, when the inter-vehicle distance control unit is in an active state.