摘要:Breakwater as coast structure is used for protecting harbor or other coast structure caused by attacked. One of coast structure i breakwater with the breakwater type structure angle side, whire is, the out of layer is protected with armour layer contain of rubblemound of stone, tetra od, cube, dolos, or kinds of other armour layer, where is, happened damage coused b ave attack. The objective of this study is to known the presentage of breakwater armour layer damage coused by irregular wave, with Bretschneider spectrum.. The m thod which be used in this study is physical model. This study was done in the po length 55 meters, with 20 meters, and height 1,25 meter. But for this experiment used width of pool 12 meter and depth 35 cm, angle direction vertically to breakwater. Armour layer which is studied contain \ tetrapod, cube and a mound stone. The weight of armour layer is calculated with Hudson formula. Running application is applied three times with the wave attack duration was 18.5 minutes, or about 1000 number waves. The experiment result with irregular wave, Bretschneider spectrum sho ed that sensor in front of the breakwater is got wave heigt of maximum (Hmax) 20.56 cm, wave heig of significant (Hs) 11.04 cm, and wave heigt of average verage) 6.84 cm and the number of wave 1065 waves. While the damage percentage e, the tetrapod armour layer 1.38%, cube 0.83 % and broken stone 1.61 %.