Influence　of　homogenization　on　mechanical　properties　of　Al-1Mn-1Mg　alloy　prepared　by　different　melt-treatments　was　discussed　and　mechanism　of　metallurgical　defects　on　ingots＇　mechanical　properties　was　analyzed.　It　was　found　that　metallurgical　defects,　such　as　the　inclusions　and　gas　holes,　cannot　be　removed　from　the　original　ingots　by　homogenization;　the　average　increasement　of　tensile　strength　of　the　ingots　prepared　by　comprehensive　melt-treatment　and　homogenized　at　400~500°C　for　12　hours　was　17.4%,　and　the　elongation　improved　slightly;　the　better　obdurability　of　the　ingots　can　be　obtained　due　to　the　vast　reduction　of　crack　initiation　of　metallurgical　defects　such　as　the　inclusions,　gas　holes　and　so　on;　the　fracture　mode　gave　priority　to　the　type　of　transcrystalline　and　micropore　gathering;　under　the　experiment　condition,　the　relatively　optimized　processing　permanents　of　homogenization　can　be　obtained　by　heating　at　450~500°C　while　holding　for　12　hours　and　air　cooling;　the　comprehensive　mechanical　properties　of　the　ingots,　prepared　by　the　optimized　process,　can　be　tested　as　follows:　σb≈180~193MPa,　δ≈16.0~18.0%.　©　Chen　et　al.