Patent analysis is the extracting knowledge which is needed for research and development strategy through accumulated worldwide patent database. In order to set the future direction of corresponding technology which is scheduled to be developed, the technology trends and deployment processes are identified by analyzing results of present patent applications. In this study, patent analysis for reverse osmosis membrane technology development was carried out. The patents in Korea, USA, Japan, and Europe were searched. 860 patents were selected relating to desalination technology upgrading reverse osmosis membrane. The technology trend reverse osmosis membrane was analyzed based on patent application year, countries, main applicants, and each technologies. The application status of reverse osmosis membrane patents showed a tendency to increase slightly. The number of patent applied was USA patent 35%, Japan patent 13.7%, EU 4.3% and Korea patent 16.7%. It will be necessary for efficient use of Desalination to support reverse osmosis membrane research and development.