An air conditioning system comprising: a first air conditioner (50-1); a second air conditioner (50-2); a first operation terminal (10-1) capable of operating the first air conditioner (50-1); a second operation terminal (10-2) capable of operating the second air conditioner (50-2); and a portable terminal to receive, from the first operation terminal (10-1), first setting information formed from first information for operating the first air conditioner (50-1) or the second air conditioner (50-2) and second information that is information on the first operation terminal (10-1) or the second operation terminal (10-2), to generate transmission information on the basis of the first setting information, and to transmit the transmission information to the second operation terminal (10-2), characterized in that the first operation terminal (10-1) and the second operation terminal (10-2) each comprise a remote controller display unit to display the first setting information, and when receiving, from the portable terminal , a transmission request signal that is a signal for requesting transmission of the first setting information, or a change request signal that is a signal for requesting change in the first setting information while a change screen to be displayed when changing the first setting information is displayed on the remote controller display unit , the first operation terminal (10-1) and the second operation terminal (10-2) each transmit, to the portable terminal , a disapproval response signal that disapproves reception of the first setting information or disapproves change in the first setting information. a first air conditioner (50-1); a second air conditioner (50-2); a first operation terminal (10-1) capable of operating the first air conditioner (50-1); a second operation terminal (10-2) capable of operating the second air conditioner (50-2); and a portable terminal to receive, from the first operation terminal (10-1), first setting information formed from first information for operating the first air conditioner (50-1) or the second air conditioner (50-2) and second information that is information on the first operation terminal (10-1) or the second operation terminal (10-2), to generate transmission information on the basis of the first setting information, and to transmit the transmission information to the second operation terminal (10-2), characterized in that the first operation terminal (10-1) and the second operation terminal (10-2) each comprise a remote controller display unit to display the first setting information, and when receiving, from the portable terminal , a transmission request signal that is a signal for requesting transmission of the first setting information, or a change request signal that is a signal for requesting change in the first setting information while a change screen to be displayed when changing the first setting information is displayed on the remote controller display unit , the first operation terminal (10-1) and the second operation terminal (10-2) each transmit, to the portable terminal , a disapproval response signal that disapproves reception of the first setting information or disapproves change in the first setting information. <EOS>