An　experimental　study　was　carried　out　to　investigate　the　energy　dissipation　characteristics　of　sea　grass　in　a　dam　break　flume.　Dam　break　flows　were　generated　in　a　flume.　A　steel　ball　was　subjected　to　the　dam　break　flow,　and　then　climbed　on　a　slope.　Artificial　sea　grass　was　used　as　the　energy　dissipation　plant.　In　the　study,　the　characteristics　(such　as　wave　height,　wave　velocity,　Froude　number)　of　the　dam　break　flow　were　investigated,　the　ball　subjected　to　the　dam　break　flow　was　observed,　some　impact　factors　of　ball　climbing　height　were　explored.　Results　show　that,　the　ball　climbing　height　increases　with　increasing　reservoir　water　level　and　decreasing　ball　diameter.　The　relative　ball　climbing　height　decreases　with　increasing　relative　distance　and　increasing　relative　grass　height.　The　relative　ball　climbing　height　shows　logarithmic　correlation　with　relative　reservoir　water　level.　The　energy　dissipation　coefficient　of　the　sea　grass　changed　with　reservoir　water　level,　with　the　average　value　of　0.34　in　this　study.