This study presents a new image inpainting method based on affine transformation for security. In the traditional image inpainting process, removed object is filled by patches in other regions of the same image. The tamper of the image is easy to be found out by copy-move detection. Thus, the usage of image inpainting in image forgery or other image security field is limited. In this study, the patch, which is used to fill the removed object, is processed by affine transform. This method is resistant to copy-move detection. The image quality is also well preserved.