Multiwavelets are an advance of the well established wavelet theory. The performance of the wavelets in the field of image processing is well known. Multiwavelets take wavelets a step ahead in performance. In this work the performance of the Integer Multiwavelet Transform (IMWT) for Lossy compression has been studied. The IMWT shows good performance with reconstruction of the images. This work analyses the performance of the IMWT for lossy compression of images with Magnitude set coding. The Transform coefficients are coded using the Magnitude set coding and run length Encoding techniques. The Transform coefficient matrix is coded without taking into account of the sign by using the Magnitude Set - Variable Length Integer representation. The sign information of the coefficients is coded as bit plane with zero thresholds. The Bit plane so formed can be used as it is or coded to reduce the bpp. The Simulation was done in Mat lab. © 2014 IEEE.