The detection problem for small targets in IR image sequences is a hot topic nowadays. In order to detect small targets in IR clutter, an algorithm based on suppressing clutter background with Wiener filter and then detecting the small targets adaptively is put forward. Experiments are done with long-range IR image sequences, and results and analyses of these results are given. The results show that this algorithm can detect small targets within the IR image sequence with SNR higher than 2.0.