Abstract: We propose a wavelet-domain Hidden Markov Tree (HMT) model-based multi-spectral and panchromatic images fusion algorithm in this study. Our algorithm exploits the wavelet-domain HMT model learnt from the high-resolution panchromatic image to perform super-resolution operation to the low-resolution multispectral image. In this way, the desired high-resolution multispectral image is obtained. The experimental results showed that the proposed algorithm can produce sharper images as well as retaining good color. Moreover, as a result of the insensitivity of the wavelet coefficients’ statistical information to the noises, our algorithm exhibits stronger robustness to the noises.