To　improve　probiotics＇　survivability　during　gastrointestinal　digestion　and　heat　treatment,　Lactobacillus　plantarum　was　microencapsulated　by　spray-drying　using　Laminaria　japonica　polysaccharide/sodium　caseinate/gelatin　(LJP/SC/GE)　composites.　Thermogravimetry　and　differential　scanning　calorimetry　results　revealed　that　the　denaturation　of　LJP/SC/GE　microcapsules　requires　higher　thermal　energy　than　that　of　SC/GE　microcapsules,　and　the　addition　of　LJP　may　improve　thermal　stability.　Zeta　potential　measurements　indicated　that,　at　low　pH　of　the　gastric　fluid,　the　negatively　charged　LJP　attracted　the　positively　charged　SC/GE,　helping　to　maintain　an　intact　microstructure　without　disintegration.　The　encapsulation　efficiency　of　L.　plantarum-loaded　LJP/SC/GE　microcapsules　reached　about　93.4%,　and　the　survival　rate　was　46.9%　in　simulated　gastric　fluid　(SGF)　for　2　h　and　96.0%　in　simulated　intestinal　fluid　(SIF)　for　2　h.　In　vitro　release　experiments　showed　that　the　LJP/SC/GE　microcapsules　could　protect　the　viability　of　L.　plantarum　in　SGF　and　release　probiotics　slowly　in　SIF.　The　cell　survival　of　LJP/SC/GE　microcapsules　was　significantly　improved　during　the　heat　treatment　compared　to　SC/GE　microcapsules　and　free　cells.　LJP/SC/GE　microcapsules　can　increase　the　survival　of　L.　plantarum　by　maintaining　the　lactate　dehydrogenase　and　Na+-K+-ATPase　activity.　Overall,　this　study　demonstrates　the　great　potential　of　LJP/SC/GE　microcapsules　to　protect　and　deliver　probiotics　in　food　and　pharmaceutical　systems.