Abstract: A device for preventing rats from climbing, characterized in that the device made of deformable plate (1), such as metal plate, comprises a plurality of adjacently arranged deformable plates (3) and a fixing part (2) for fixing the plurality of deformable plates to a pipe/rod (10) or other desired body which climbing rats is to be prevented. Each of the deformable plates has sharp teeth and/or protrusions at its edges and has an end connected to the fixing part. It is possible for the user to deform and extend the deformable plates in various directions by using tools, so as to form sharp construction around the contour of the pipe/rod (10), thereby preventing rats from climbing. Moreover, the fixing part is provided with a punched structure, through which fixing members such as screw, rope and steel sheet can penetrate for fixing the device or for connecting the device to other device.