Sample　deposition　based　on　micro-droplet　ejection　has　broad　application　prospects　in　the　field　of　biomedicine.　Ejection　of　RPMI-1640　medium　(without　and　with　cells)　is　investigated　experimentally　using　a　home-build　electrohydrodynamic　(EHD)　ejection　system,　consisting　of　a　liquid　supplier　and　a　nozzle,　a　high　voltage　source,　a　droplet　collector,　and　a　high　speed　photography　module.　Electric　voltage　is　applied　between　the　nozzle　and　the　droplet　collector.　The　liquid　surface　is　charged　and　the　ejection　takes　place　when　electric　force　overcomes　the　surface　tension.　The　ejection　process　is　studied　by　using　high　speed　photography　and　image　processing.　At　low　voltage,　a　uniform　ejection　state　is　established　with　ejection　frequency　typically　less　than　50Hertz.　At　sufficiently　high　voltage,　another　uniform　ejection　state　is　reached　with　ejection　frequency　as　high　as　1300Hz.　Human　peripheral　blood　mononuclear　cells,　after　ejection,　show　survival　rates　higher　than　79%,　manifesting　EHD　ejection　as　a　promising　technique　for　cell　printing.