Tools are needed to have access to more effective information and to select it in the environment of digital information where information pours in. and some of the advanced techniques to make up these tools are metadata and annotation. Annotation additionally records the marks for the supplementary explanation of and emphasis on a specific part of the original text and kas more various merits than metadata in terms of the search and use of digital resources. This research aims at suggesting methods that annotation. which has a range of functions including access to information. its reuse and sharing in the digital surroundings of late, can be applied to digital contents such as web services, digital libraries and electronic books. As to the research method, the case studies of annotation systems applied to web services and digital libraries have been carried out, and the metadata formation of the systems has been analyzed.