Abstract: In order to enable the fused image to maintain multi-spectral characteristics of the original IKONOS satellite images and improve the image space resolution to its utmost limits,a new image fusion method based on quad-tree complex wavelet packet transform(QCWPT) is presented for multispectral IKONOS satellite image and SAR(Synthetic Aperture Radar) image,and the proposed image fusion method employs the multi-directional characteristics and excellent local time-frequency analysis ability of QCWPT for high frequency detail signals.The I component sub-image of the multispectral IKONOS satellite image via HIS space transform and the SAR image are decomposed separately by using the QCWPT.The low frequency complex wavelet packet coefficients are fused by using an average or large-value fusion method,and the high frequency complex wavelet packet coefficients are fused via a new fusion method,namely,a locally adaptive fusion method for neighborhood homogeneous measurement.The original I component sub-image of the multispectral IKONOS satellite images is replaced by the reconstruction image via reverse QCWPT.So,the last fusion image can be obtained via HIS space reverse transform.Experimental results show that the presented fusion algorithm is of higher performance than other traditional fusion methods in spectrum reservation and space quality improvement.