Sample　deposition　based　on　micro-droplet　ejection　has　broad　application　prospects　in　the　field　of　biomedicine.　Ejection　of　RPMI-1640　medium　(with　and　without　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.　High　electric　voltage　is　applied　between　the　nozzle　and　the　droplet　collector.　The　liquid　surface　is　electrically　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　stable　ejection　state　is　established　with　ejection　frequency　ranging　from　a　few　to　a　few　tens　of　Hertz.　At　high　voltage,　another　stable　ejection　state　is　reached　with　ejection　frequency　as　high　as　1300Hz.　At　the　transition　voltage　range,　the　ejection　exhibits　a　periodic　behaviour.　During　each　cycle,　the　meniscus　rapidly　oscillates　with　gradually　increased　amplitude,　and　with　several　non-uniform　droplets　ejected　at　the　final　stage　of　the　cycle.　Human　peripheral　blood　mononuclear　cells,　after　ejection,　shows　survival　rates　higher　than　79%,　manifesting　EHD　ejection　as　a　promising　technique　for　cell　printing.