A digital broadcasting system and a data processing method are disclosed. The receiving system of the digital broadcasting system includes a baseband processor, a first handler, a second handler, and a storage unit. The baseband processor receives a broadcast signal including mobile service data and main service data. Herein, the mobile service data may configure an RS frame, and the RS frame may include the mobile service data and first signaling information of a first data type on the mobile service data. The first handler parses the first signaling information received from the RS frame, converts parsed data elements of the first data type to a second data type, and merges multiple identification information of the parsed first data type, thereby generating identification information of the second data type. The second handler receives second signaling information of the second data type on the mobile service data, the second signaling information including at least one fragment, uses the identification information of the second data type included in the first handler to search at least one fragment within the second signaling information, and maps data elements received through the searched fragment with the data elements converted to the second data type.