Cascaded　mid-infrared　(MIR)　Er　:　YAG　pulsed　lasers　at　room　temperature　are　reported.　The　characteristic　wavelength　of　the　cascaded　emission　is　experimentally　observed　to　be　1469　nm,　and　that　of　the　excited-state　absorption　is　determined　as　1676　nm.　Er:　YAG　crystals　with　doping　concentrations　(atomic　number　fractions)　of　7.5%　and　10%　are　adopted　to　compare　the　MIR　output　energy　under　the　cascade　and　non-cascade　conditions.　For　the　Er:　YAG　with　a　doping　concentration　of　7.　5　,　the　maximum　single　pulse　energy　of　MIR　laser　increases　from　0.62　mJ　(non-cascade)　to　0.　99　mJ　(cascade),　increasing　by　about　59.　7%,　and　for　Er　:　YAG　with　a　doping　concentration　of　10%,　that　increases　from　1.　04　mJ　(non-cascade)　to　1.　51　mJ　(cascade),　increasing　by　about　45.2%.　The　experimental　results　confirm　the　existence　of　cascade　output　at　room　temperature　in　low-doped　Er:　YAG　crystals.　The　cascade　is　helpful　to　improve　the　single　pulse　energy　of　the　mid-infrared　laser.