Summary: The purpose of super resolution(SR) is to reconstruct a high-resolution(HR) image with a higher quality version effect from one or a sequence of low-resolution(LR) images, which are captured from the same scene and subsampled as well as shifted with sub-pixel precision. The resolution enhancement technique of super resolution has been widely applied recently, for example, the computer version and image processing. With the research of image degradation model, reconstructing images in the spatial domain becomes more and more popular. In this thesis we focus on super-resolution reconstruction methods of zooming image sequence. However, these methods do not pay enough attention to the situation where the size of target in the zooming image sequence changes greatly. In this thesis we focus on super-resolution reconstruction methods of zooming image sequence. Firstly, we present zooming degradation model based on the low-resolution image sequence. A target-size image produced from LR image by interpolation is then selected as the initial high-resolution image. Based on the degradation model and the matching points generated by scale-invariant feature transform(SIFT) respectively in HR and LR image, the transform formula is proposed. By this transform formula, a simulated LR image is generated from the HR image. Then we compute the difference between the simulated LR image and the real observed LR image mentioned in computing transform formula. When the difference is higher than some threshold, the difference is added into the HR image by back projection so that the HR image is updated. Finally, the improved algorithm is employed on simulated zooming LR image sequence and real zooming LR image sequence. Peak signal to noise ratio(PSNR), structural similarity index(SSIM) and energy ratio between high-frequency components and the whole image are calculated to evaluate the quality of our rebuilt HR image. The experimental results show that the HR image reconstructed by our proposed SR algorithm with zooming LR image sequence has achieved good image quality.