Objective: To identify and preliminary screening on the biodiversity of marine seaweeds and sea fans extract against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus in Puducherry. Methods: Monthly wild seaweeds were collected from coastal region of Puducherry. The identified seaweeds and sea fans were authenticated from the regional centre of CMFRI, Chennai. All the collected samples were washed thrice with tap water and twice with distilled water to remove the adhering salts and other associated animals. Results: 44 species of seaweeds and three species of sea fans were identified, belonging to three families such as, Phaeophyta (16 species), Rhodophyta (14 species), Chlorophyta (14 species) and three sea fans were collected from the Puducherry coast. Conclusion: From the results it can be concluded the coastal region of Puducherry highlights the ambient habitat for dominant occurrence of Phaeophyta, Rhodophyta and Chlorophyta species of sea fans having bioactive potentials against larvicidal, ovicidal activities for mosquitoe vectors.