本文主要目的是在研究不同佈置之離岸潛堤對反射率及堤趾沖刷的影響。實驗的過程可分為兩部分（1）主要在探討單一波高下、不同週期及離岸潛堤佈置時波浪通過離岸潛堤所造成的反射率的影響。（2）在動床實驗則針對堤趾沖刷作進一步分析，探討沖刷深度與反射率、堤寬比、堤深比、週期的關係。研究結果顯示反射率K/sub R/與B/h無直接關係，但其隨堤深比R增大而變大、隨週期T增大而增大，在對ka方面反射率最大值出現在ka=0.42-0.52間，最小值出現在 ka=0.46-0.6間。在離岸堤堤趾沖刷方面，研究結果顯示堤趾沖刷隨著堤深比的增加而增加、隨週期的增大而增加，但與反射率及B/h則無顯著關係。 A series of experiments had been conducted to study the effects of an offshore submerged breakwater on the reflection coefficient and toe erosion. This study consist of two parts. (1) By using different wave periods, the ratios (B/h) and R's, we examined those effects on reflection coefficient. (2) We had also discussed these parameters(K/sub R/, T, B/h, R) on erosion depth at the toe of submerged breakwater. The results showed that there is no direct relation between K/sub R/ and B/h. As R or T is increased, K/sub R/ is also increased. The maximum ka occurred at ka=0.42-0.52, and the minimum ka happen between ka=0.46-0.6. The toe erosion depth increase as R or T is increased. The data had also shown that there are little relation between toe erosion depth and K/sub R/ or B/h.