The present invention relates to a heterogeneous network-based linked broadcast content transmitting/receiving system and method. A transmission system generates a basic content stream on basic content constituting broadcast content and transmits the generated basic content stream to a terminal through a broadcast network, and also generates an additional content stream on additional content linked to the basic content and transmits the generated additional content stream to a terminal through a communication network. At least one of linkage playback information on the basic content and linkage playback information on the additional content is further transmitted to the terminal. Additionally, a reception terminal receives the basic content stream, the additional content stream, and the linkage playback information, and then synchronizes the basic content with the additional content and plays them back in order to playback broadcast content in real time.