In passive bistatic radar system with orthogonal frequency division multiplexing (OFDM) waveform, the power of the target echoes is much weaker than the power of directpath wave and that of multipath echoes, so multipath clutter suppression is a key technology of radar signal processing. Many temporal adaptive filtering algorithms are used to suppress multipath clutter, but they often have the problems of long filter order and high computational burden. Based on the multicarrier modulation of OFDM waveform, this paper proposes a subcarrier adaptive filtering algorithm. It can effectively reduce the order of filter and computational complexity compared with the traditional temporal adaptive filtering algorithm. This paper, taking digital radio mondiale-based passive bistatic radar which employs OFDM technique for example, introduces the adaptive filtering processes of recursive least square by subcarrier and normalized least mean square by the subcarrier algorithm in detail. Furthermore, the performances of the traditional temporal adaptive filtering algorithm and the subcarrier adaptive filtering algorithm are further analyzed.