This study focused on a small gastropoda, Cerithium zonatum, found in seagrass meadow at Gui Wan Bi, Green Island, Taiwan. Because this species is high in density in the seagrass meadow and it uses its specific radular to scrap the substrate and emits a particular sound, we can use this acoustic clue to study its feeding activity. C.zonatum samples were collected from Gu Wan Bi, and Zi-Ping Green Island between November to December 2007,March to June 2008, and April to July 2009. It distributes in three habitats (i.e. seagrass¡Bmacro algae¡Brubble) and scrapping sounds were recorded while they were in these habitats. Light and water temperature were treated as experimented factors and their influence on the feeding frequency was deciphered. I also compared individuals of different sizes to find out the differences in feeding frequency between them. SEM was used to observe the radular of C. zonatum. According to the results, I infer that C. zonatum might prefer seagrass meadow as its must suitable microhabitat where feeding activity was higher. Sunlight and high water temperature might lead to increases in feeding activity, but darkness and low water temperature showed opposite effect; it stopped feeding when water temperature had dropped to 17¢J. Scrap frequency of small individuals was higher than larger ones, and their radular were similar in their morphology. I infer that small ones invest more time and energy in feeding in order to grow. Scrapping sound of C.zonatum was compared to Nerita albicilla; there were pulses in the sound of N.albicilla than C. zonatum. It is inferred that this difference might be due to the difference between their radular morphology. I consider that using an bioacoustic approach to study the feeding activity of small gastropoda is feasible.