An Image fusion is the development of amalgamating two or more image of common characteristic to form a single image which acquires all the essential features of original image. Nowadays lots of work is going to be done on the field of image fusion and also used in various application such as medical imaging and multi spectra sensor image fusing etc. For fusing the image various techniques has been proposed by different author such as wavelet transform, IHS and PCA based methods etc. In this paper literature of the image fusion with wavelet transform is discussed with its merits and demerits.