Abstract: This study aims to offer ways that could be used to estimate the capacity of dumping area. The capacity will be concluded from the largest instantly dumping capacity and the largest acceptable deposition. The largest instantly dumped strength depends on whether the suspensions would have harmed the water quality protection in and around the dumping site.Similarly， the largest acceptable sedimentation lies on whether the sedimentation by dumping strength have hindered the navigation function on and around the dumping site for the acceptable settlement depth.In this case we discuss the acceptable dumping capacity to the ecological sensitive dumping area when acceptable amount （36 000 m³）of instantly maximum dumping taking the Sheng si Shang chuan shan marine dumping area as example.Moreover，we estimate that the capacity of this dumping area are approximately in range of 1 500×10⁴ m³ to 2 000×10⁴ m³. We set the sedimentation influence on the depth by dumping under different dumping cases at 1 500×10⁶， 4 000×10⁴ m³ and 6 000×10⁴ m³ in 7 months in order to know the levels of sedimentation at the sensitive depth target at and around the dumping site. At last we determine that the acceptable sedimentation dumping capacity is at the level of 1 500×10⁴ m³．