A digital broadcasting system and a data processing method are disclosed. A receiving system of the digital broadcasting system includes a baseband processor, a first table handler, an audio/video processor, and a content processor. The baseband processor receives a broadcast signal including mobile and main service data. The mobile service data may configure an RS frame, and the RS frame may include mobile service data for mobile audio and/or video broadcasting, a first table describing at least one channel configuration information on the mobile service data, and a second table transmitting content for data casting service. The first table handler parses the first table from the RS frame, thereby acquiring at least one channel configuration information on the mobile service data. The audio/video processor extracts mobile service data of a mobile broadcast program requested for viewing from the RS frame, by referring to the channel configuration information of the first table handler, and decodes the extracted mobile service data, thereby outputting the decoded data to a speaker and/or a display screen. And, the content processor parses the second table from the RS frame to extract content, and processes the extracted content based upon an information associated with the extracted content.