A push service device for balancing message loads includes: a service provider (SP) interworking unit to connect with a service providing device; a controller to route a push message received from the service providing device through the SP interworking unit to one or more corresponding client devices; and a client interworking unit to transmit the push message transferred from the controller to the one or more corresponding client devices, to receive a keep-alive message from at least one of the one or more corresponding client devices, and to transmit a keep-alive configuration message to the one or more corresponding client devices to disperse reception time points of the keep-alive message for a predetermined transmission period of the keep-alive message when the reception time points of the received keep-alive message are synchronized.