With the remarkable development of digital medical images and high-speed transmission networks and computer technologies in current year, authenticity and security of the medical images have been big issues for E-health application. In order to this many different remarkable watermarking strategies and concepts have been introduced by researchers. In this paper we concentrate on the possibilities for assurance of medical images using the principle of digital watermarking. There are many methods it looks from their basic perspective. One of them perspective is security to ensure authenticity and copyrights. Other we discuss watermarking methods classification which are based on different parameters such as: insertion domain (spatial and frequency domains)..