The　microencapsulation　of　biomaterials　has　a　broad　application　prospects　in　the　field　of　biomedicine.　This　paper　introduces　design　and　setup　of　a　coaxial　microcapsule　generator　based　on　electrohydrodynamic　(EHD)　method.　It　includes　a　liquid　supply　system,　a　coaxial　nozzle,　a　collector　electrode,　and　a　high　voltage　power　supply.　The　ejection　process　is　studied　via　LED　illumination　and　a　high　speed　CMOS　camera.　For　the　shell　and　core　materials,　alginate　and　RPMI-1640　culture　medium　are　applied　respectively.　The　effects　of　electric　voltage　and　flow　rate　on　the　ejection　frequency　and　volume　of　micro-droplet　are　investigated.　The　generated　micro-droplets　react　in　the　collector　electrode　with　CaCl2　solution.　Alginate　hydrogel　microcapsules　are　produced　with　RPMI-1640　included.　Good　encapsulation　is　confirmed,　by　fluorescence　microscopy,　and　with　RPMI-1640　stained　by　sodium　fluorescein.　The　produced　microcapsule　may　be　used　in　biological　cell　encapsulation,　in　the　future.　©　Published　under　licence　by　IOP　Publishing　Ltd.