The purpose of this study is to incorporate the knowledge and technique of marine geotechnical engineering, underwater acoustic surveying and hydraulic experiment into studying the problems of artificial reefs off Ling-yang, Kaohsiung Country, South-western part of Taiwan deployed in March 1996. Based on hydraulic experiment, we try to observe the scouring mechanism of artificial reefs. Beside, two other reefs Yung-an, Fang-lio reef were surveyed in this study .The ultimate goal of this investigate was intended to deduce ways to solve the problem of excessive scouring and subsidence, and decide the appropriate environment of the seafloor to deploy artificial reefs for promoting fishing developing. The topography of Ling-yang is generally gentle. Based on the test of physics and mechanics, most surficial sediments at the surface was cohesiveless sand sediments including a lot of seashell. Therefore, we deduced that the surficial sediments are easier to drift caused by monsoon and typhoon in summer. The phenomenon indicated that the surface of sediments is unstable when the sediments are cohesiveless or were loaded by other forces. This study showed that there were obvious scouring effect occurred in and around the reefs, Ling-yang, Yung-an and Fang-lio. The most serious scouring area was occurred in Ling-yang, and a majority of reefs have been buried there. Therefore, the major factors, which could induce excessive subsidence or undermining of the artificial reefs in the testing site, were proposed to be scouring effects. Compared with other reef areas, the scouring effect was related to the grain distribution on the seafloor and the velocity of currents. In the aspect of preventing subsidence of reefs, the reefs closely deployed were better than that loosely deployed.