To　prepare　a　kind　of　super-absorbent　polymers　by　gracilaria　lemaneiformis　residue,　a　novel　super-absorbent　polymer　was　synthesized　by　means　of　microwave　irradiation.　Acrylic　acid　and　acrylamide　were　grafted　onto　gracilaria　lemaneiformis　residue　by　using　potassium　per-sulfate　as　an　initiator　in　the　presence　of　N,　N＇　-　methylenebisacrylamide　as　a　cross　linker.　The　univariate　analysis　was　visually　analyzed　to　choose　the　optimal　conditions.　The　optimum　conditions　show　that　the　initiator　dosage　is　0.5　%,　the　cross　linker　dosage　is　0.04　%,　the　mass　ratio　of　acrylic　acid　and　acrylamide　is　5:2,　the　neutralization　degree　of　acrylic　acid　is　80　%,　the　time　of　microwave　irradiation　is　4　min,　the　mass　ratio　of　gracilaria　lemaneiformis　residue　and　monomers　is　1:2　and　the　power　of　microwave　irradiation　is　500　W　respectively.　Under　the　optimum　condition,　the　absorption　capacities　of　the　resultant　product　for　the　deionized　water,　tap　water　and　0.9　%　NaCl　solution　can　reach　650.1　g/g,　468.5　g/g　and　104.3　g/g,　respectively.　The　performance　test　of　the　resultant　product　indicates　that　it　has　faster　absorbent　velocity　and　excellent　water　retention.　©　2011　IEEE.