A digital broadcasting system and a data processing method are disclosed. A receiving system of the digital broadcasting system includes a baseband processor, an IP network stack, and a handler. The baseband processor receives a broadcast signal including mobile service data and main service data. Herein, the mobile service data configures a Reed-Solomon (RS) frame, and the RS frame includes mobile service data and an internet protocol (IP) signaling channel having pre-decided IP access information included therein. The IP network stack accesses the IP signaling channel from the RS frame using the IP access information, thereby collecting signaling table information received through the IP signaling channel. And, the handler identifies and parses the collected signaling table information based upon a table identifier of each signaling table received through the IP signaling channel, thereby storing the parsed result.