In order to understand the feeding ecology of Agrammus agrammus in the rocky reef habitat off the Ma'an Archipelago Special Marine Reserves, the dietary composition and feeding strategy of Agrammus agrammus were analyzed based on the 252 fish samples collected from March, 2009 to February, 2010. The results showed that A. agrammus mainly preyed on Amphipoda (Caprellidae) and was a specialized feeder on Caprellidae. The diet of A. agrammus showed significant seasonal patterns, and was dominated by Amphipoda (Caprellidae) in spring, summer and autumn and crabs, gastropods and others in winter. Agrammus agrammus showed a specilized feeding strategy in spring, summer and autumn and genralized feeding strategy in winter.