The application of science and technology to all areas, including medicine, is an inevitable trend of the 21 st century. With its rapid development and significant achievements, science and technology have been contributing to many disciplines of medical field. However, there are many factors that may hinder the application of science and technology in clinical practices. A clear recognition of these difficulties of the nature of medical research is the basis for policy formulation and decision making towards a proper and efficient application of such advancements.