An air conditioning system and a controlling method of the same are provided. A controlling method of an air conditioning system includes an information collecting step configured to collect the state information or the operation information of the outdoor unit or the indoor unit in a preset period by using the gateway, an information transferring step configured to selectively transfer the information collected in the information collecting step to the data collecting server in a preset period, an information storing step configured to transfer the operation information or the state information of the outdoor unit or the indoor unit out of the information transferred in the information transferring step to the data storage server and to store the transferred information in a preset period; and an information outputting step configured to output the state information or the operation information of the outdoor unit or the indoor unit transferred in the information transferring step to the output unit at predetermined intervals shorter than the preset period using the data collection server, when there is information transfer requirement.