In　present　study,　effect　of　heat　treatment　conditions　on　the　microstructure　and　magneto-caloric　effect　of　Gd5Si2Ge2　alloys　prepared　from　high-purity　distilled　Gd　was　discussed.　Microstructure　and　the　chemical　composition　of　the　alloys　were　investigated　by　using　scanning　electron　microscope　(SEM)　with　energy　dispersision　X-ray　spectroscopy　(EDX).　Magnetization　behaviors　of　alloy　from　250　K　to　290　K　in　the　magnetic　field　under　1.6X10(6)　A/m　were　measured　by　means　of　vibrating　sample　magnetometer　(VSM)　and　the　maximum　magnetic　entropy　was　calculated　according　to　the　Maxwell　equations.　It　is　found　that　the　microstructure　of　the　alloys　can　be　fully　homogenized　and　the　impurities　in　the　alloys　can　be　remarkably　removed　via　appropriate　heat　treatment.　As　a　result,　the　maximum　magnetic　entropy　of　the　alloys　increases　by　200%　while　the　magnetic　ordering　temperature　slightly　reduce　about　10　K.