The　packing　characteristics　of　aggregates　are　very　important　for　aggregate　blend　design,　which　is　closely　related　to　the　performance　of　mixtures.　In　this　study,　an　indoor　packing　experiment　was　designed　to　investigate　the　behaviors　of　single-size　particle　packing　and　two-size　particle　packing.　The　effects　of　particle　composition,　particle　size　and　size　ratio,　particle　morphology　on　packing　characteristics　were　also　evaluated.　Two　kinds　of　aggregates　(crushed　stone　and　gravel)　with　significant　morphological　differences　were　selected　for　the　test.　The　angularity　of　the　aggregates　was　quantitatively　analyzed　using　the　variance　of　mean　curvature　(S-Cm(2))　of　particle　surface　in　accordance　with　the　3-D　scanning　measurements.　Based　on　the　test　results,　the　packing　characteristics　of　aggregates　were　analyzed　using　the　air　void　content　(V-a)　and　the　packing　function　index　(I-pf)　proposed　in　this　paper.　It　is　shown　that　the　analysis　results　of　packed　ideal　spheres　cannot　be　directly　used　to　describe　the　packing　characteristics　of　aggregates.　Particle　morphology　has　a　significant　impact　on　packing　characteristics,　especially　on　the　V-a.　The　V-a　of　packed　aggregates　with　poor　angularity　is　significantly　smaller　than　that　with　good　angularity.　I-pf　can　be　used　to　quantitatively　distinguish　the　packing　function　of　particles.　The　test　results　show　that　the　packing　function　of　particles　cannot　be　simply　divided　into　the　skeleton　building　and　air　voids　filling.　Generally,　the　particles　in　packed　blend　have　both　of　these　functions.　The　packing　function　of　particles　depends　not　only　on　the　particle　size,　but　also　on　the　composition　of　particles　with　different　size.　When　the　size　ratio　and　volume　ratio　are　the　same,　the　packing　characteristics　of　the　two-size　particle　blends　will　still　change　with　the　change　of　the　particle　size.　The　exploration　of　packing　behaviors　of　single-　size　and　two-　size　particle　aggregates　is　helpful　for　analyzing　the　packing　behaviors　of　blends　with　multi-size　particles.