Background: Corals have a diversity of prokaryotic communities as an internal or external symbiotic . This review will examine the association between corals and their symbiotic microorganisms from the ecology and biotechnology perspective. Material and Methods: In this study, articles were examined which indexed in Pubmed, Science Direct, Google Scholar and Scirus databases. Keywords we used included coral, symbiotic microorganisms, ecology, and biotechnology. Finally, overall of 120 articles and reports, 103 articles were evaluated by eliminating the same articles. Results: The Corals symbiotic microorganisms stay on in the ecological niches such as the surface mucus layer, tissue and their skeleton. They play role in the cycle of sulfur, nitrogen fixation, production of antimicrobial compounds and protect corals against pathogens. Many bioactive compounds which attributed to invertebrates such as sponges and corals in fact they are produced by symbiotic bacteria. Various metabolites produced by these microorganisms can be used as medicine. Five screening strategies including conventional screening, met genomics, genomics, combinatorial biosynthesis, and synthetic biology are used for marine microbial natural products discovery and development. Conclusion: According to the collected material we can be concluded that, the ecological studies about the natural association between corals and their symbiotic microorganisms were technological prerequisite for biomedical research and they make clear the road to attainment to bioactive compounds in fauna. Also, in the first step, it is recommended that modern technology and advanced screening methods used to identification of marine organisms and then to identify secondary metabolites among them.