Abstract:This paper provides an overview of the equilibrium sensory organ structures in Coelenterate. Statocyst lacks cilia at the end of the holdfast in fairy palm Corymorpha palma. Open and closed statocysts lie on the bell margin of Leptomedusae. The statocysts of Narcomedusae lie on the exumbrellar surface just above the exumbrellar nerve ring, with a sensory club (Aegina) and a sensory papilla carrying a sensory club (Solmissus). The statocysts of Trachymedusae lie around the margin above the exumbrellar nerve ring. Rhopalia locate on the edge of the umbrella in Scyphozoa and slightly above umbrella edge in Cubomedusae. Statocysts or apical organs of Ctenophores locate at the aboral end of the bodies. This article has great significance for understanding the structures and functions of equilibrium sensory organs of aquatic invertebrates, and it might also be a useful supplement to the current zoological textbooks.