Abstract: An elastic wave technique is used to measure the properties of coral reef rock of core Nanyong 1 and other coral reef samples From the result the relation of wave velocity with depth is determined General trend of longitudinal wave velo city is studied from the development history,sedimentology, petrology,sedimentar y cycles and palaeomagnetic chronology The relation of longitudinal wave veloci ty with ages, texture and types of rocks, porosity, sedimentary environment of c oral reef rock, and geological events is analysed. It shows that anomalous value s of longitudinal wave velocity are the consequence of integrated effect of the se geological factors. The study of elastic wave properties is of important sig nificance in coral reef geology and can be used in the structural and stability analysis of coral reef.