In　this　paper,　uniaxial　compression　tests　were　carried　out　on　nine　concrete　specimens　with　different　coarse　aggregate　particle　size　ranges　in　single　and　continuous　gradation　at　curing　ages　of　3,　7　and　28　d,　respectively.　The　acoustic　emission　(AE)　and　microseismic　(MS)　signals　of　the　whole　loading　process　were　monitored　by　combining　AE　and　MS　to　investigate.　The　AE　and　MS　signals　characteristics　of　concrete　with　different　coarse　aggregate　gradations　during　load　damage　at　different　curing　ages　were　analyzedand　the　effect　of　the　maximum　coarse　aggregate　size　on　the　damage　evolution　of　concrete　were　investigated.　Based　on　findings　from　experiments,　as　the　maximum　particle　size　of　the　coarse　aggregate　increases,　the　initial　defects　within　the　concrete　specimens　initially　decrease　and　then　increase.　A　larger　size　and　the　more　heterogeneous　of　the　coarse　aggregate　has　an　accelerating　effect　on　the　emergence　and　expansion　of　cracks　throughout　the　load-induced　damage　process　in　concrete　structures.　In　addition,　when　the　curing　age　is　brief,　the　expansion　of　internal　cracks　in　concrete　predominantly　depends　on　the　curing　age,　with　the　relationship　to　the　maximum　particle　size　of　coarse　aggregate　being　less　evident.　©　The　Author(s),　under　exclusive　licence　to　Shiraz　University　2024.