Abstract: The stability against overturning is an important part to calculate the stability of the embedded foundation breakwater under wave loading. In this article, it is assumed that the stability of a new embedded bucket breakwater mainly depends on the horizontal soil pressures on the wall and the bottom of the bucket, and the vertical shear force on the wall and the bottom of the bucket, and that such a breakwater works in a similar principle as a retaining wall. In this study, the supposition is made that the bucket rotates around the rotating centre, as a result, soil near the wall of the harbor side is in a passive state, and soil near the wall of the sea side is in an active state. At the same time, the supposition is also made that the soil mass of the passive side under the bucket reaches a limit state. Because of the partitions in the lower bucket, it is assumed that the bucket and the soil mass in the bucket deform together, i.e. the bucket and the soil mass in the bucket are regarded as an entirety. Based on the above-mentioned hypothesis, by means of derivation and analysis, the expression of soil pressure and the friction on the bucket wall, the reaction and the friction under the bucket are deduced. A three-dimensional computation method for stability of the new embedded bucket foundation breakwater is thus developed. Finally, by analyzing the numerical model and comparing of the centrifugal tests, it is found that the computation method for the stability against overturning is reliable.