The small target detection in infrared image is one of the crucial techniques for the precision guided weapon. Using wavelet and contourlet multi-scale analysis to detect small targets in infrared image has certain limitations. non-subsampled Contourlet transform (NSCT) is a new extension to contourlet transform. It is flexible multistage and shift invariant multidirectional. This paper presents a new small infrared target detection approach

which is based on nonsubsampled contourlet transform. This method picks up the texture characteristic from the maps after nonsubsampled contourlet transform

and calculates the distance between the characteristic vector and the center characteristic vector. This can gain a correlative multi-scale distance map. The histogram of distance map is employed for the automatic selection of threshold value. The experimental results are shown

and compared with the results based on wavelet transform in terms of detection precision and speed . The results show that the method of small infrared target detection based on nonsubsampled contourlet transform can precisely detect the small infrared target and it is better than the method based on wavelet transform.