In　this　study,　in　order　to　obtain　excellent　mechanical　properties　in　TiB2/Al-Cu-Mn-Cd　composite,　an　optimized　heat　treatment,　i.e.,　short-time　solution　treatment　at　535　degrees　C　for　1　h　following　long-time　solution　at　523　degrees　C　for　11　h,　and　aging　treatment,　i.e.,　aged　at　170　degrees　C　for　12　h,　is　proposed.　In　addition,　this　study　investigated　the　connection　between　microstructure　evolution　and　mechanical　properties　during　heat　treatment.　The　results　show　that　with　adoption　of　the　optimized　solution　treatment,　the　area　fraction　of　second　and　eutectic　Al2Cu　phases　decreased　from　5.08%　in　the　as-cast　state　to　less　than　0.36%　owing　to　improvement　of　dissolution　efficiency　in　the　high-temperature　short-time　solution.　Comparing　mechanical　properties　of　the　composite　in　the　as-cast　state　and　in　the　peak-aged　state,　average　ultimate　tensile　strength　and　yield　strength　increased　from　211.9　MPa　to　523.0　MPa　and　from　115.8　MPa　to　451.8　MPa,　respectively.　However,　average　elongation　slightly　decreased　from　8.78%　to　8.24%.　Strength　contribution　of　the　peak-aged　TiB2/Al-Cu-Mn-Cd　composite　was　mainly　ascribed　to　Cd-rich,　theta　＇＇　and　theta　＇　precipitates.　In　the　peak-aged　state,　number　density　and　average　diameter　of　the　plate-like　theta　＇＇　and　theta　＇　precipitates　reached　4.266　x　10(21)　m(3)　and　64.30　nm,　respectively,　and　severe　lattice　distortions　occurred　around　the　Cd-rich　precipitates,　providing　the　strongest　precipitation　strengthening.　These　findings　indicate　that　the　two-stage　solution　treatment　successfully　solved　the　problem　of　the　eutectic　phase　at　the　triangular　grain　boundary　being　difficult　to　dissolve　in　a　TiB2/Al-Cu-Mn-Cd　composite,　and　excellent　mechanical　properties　were　acquired　with　the　optimized　aging　treatment.