As for low resolution of remote sensing images，a novel fuzzy reasoning fusion algorithm by nonsubsampled contourlet transform was proposed.Firstly，the multi-spectral image is converted from RGB space to IHS space through IHS transform.Next，with nonsubsampled contourlet transform and weighted average fusion rules based on fuzzy reasoning，the component intensity and panchromatic image are merged into a grayscale image.Finally，the stretched grayscale fused image replaces the original component intensity，and then the final fused image is achieved by inverse IHS transform.The experimental results show that the proposed method not only can obtain better effect on restraining spectral information distortion and enhancing space definition than other multi-resolution analysis methods，but also avoid some of the well-known problems in common fusion processes such as blurring effects and high sensitivity to noise.