The　strain　rate　effects　of　close-celled　aluminum　foams　with　different　porosities　were　experimentally　and　numerically　investigated　at　different　strain　rates.　It　is　found　that　the　dynamic　deformation　behavior　of　aluminum　foams　with　same　porosity　is　similar　to　their　quasi-static　behavior　in　the　strain　rate　ranging　from　0.001　s-1to　2500　s-1.　The　strain　rate　effects　of　aluminum　foams　with　varying　porosities　are　significantly　different　due　to　different　deformation　modes.　The　strain　rate　sensitivity　of　aluminum　foams　originates　mainly　from　that　of　their　matrix　material,　while　the　effects　of　micro-inertia,　shock　wave,　and　compressed　air　pressure　in　cells　are　negligible.