The lighting system includes a plurality of lighting apparatuses and a controller configured to control the lighting apparatuses. Upon receiving a random number generation instruction from the controller, the lighting apparatus generates a first random number and a second random number by using a random number generation unit, and counts synchronization signals sent from the controller. When acknowledging that the counted number of the synchronization signals is equal to the first random number, the lighting apparatus sends the second random number to the controller. The controller identifies the lighting apparatuses based on the second random numbers respectively received from the lighting apparatuses, and uniquely allocates mutually different addresses to the respective identified lighting apparatuses.