A reception system and a method for processing data in the reception system are disclosed. The reception system includes a baseband processor receiving a broadcasting signal including mobile service data and main service data, the mobile service data including first service data and second service data having a format different from that of the first service data, the second service data configuring a Reed Solomon (RS) frame, and the RS frame including a table which describes the second service data and signaling information of the second service data, a table handler parsing the table from the RS frame and extracting the signaling information of the second service data, and service handlers parsing the second service data from the RS frame on the basis of the extracted signaling information of the second service data. Accordingly, it is possible to transmit/receive service data having a format different from that of the existing method in a single MH system.