Dispersion　of　nanoalumina　in　normal　saline　(NS)　and　phosphate　buffered　saline　(PBS)　was　studied.　The　effects　of　different　dispersing　methods　were　investigated.　The　results　showed　nanoalumina　was　better　dispersed　in　NS　than　PBS.　And　sonication　was　a　more　effective　method　that　helped　deaggregation　compared　with　vortex　oscillation.　Finally,　the　influence　of　sonication　time　on　the　particle　size　and　the　stability　of　the　sonicated　NS　suspension　were　studied　using　dynamic　light　scattering.　The　aggregation　size　was　decreased　to　about　130　nm　after　ten-minute　sonication　and　maintained　when　increasing　sonication　time.　The　particles　would　aggregate　again　during　the　storing　time.　The　results　of　this　study　need　to　be　taken　into　account　prior　to　dosing　in　nanoalumina　toxicology　studies.