In　order　to　meet　the　rapidly　growing　and　changing　needs　of　mobile　instant　messaging　(IM),　this　paper　provides　a　new　service　model　and　implementation　mechanism　based　on　Jabber　and　hierarchical　thinking.　The　communication　protocol　of　our　system　provides　an　open,　expandable,　real-time　communication　technology　that　can　be　used　to　build　a　wide　range　of　XML　applications.　We　use　Linux　C++,　MySQL,　and　protocol　conversion　technology　to　develop　the　services　of　server　and　use　J2ME　technology　to　develop　mobile　client　software.　The　system　uses　the　newest　network　technology　to　supply　WAP　access　and　provide　Web　services.　It　is　demonstrated　by　experiment　that　the　system　based　oil　the　hierarchical　model　can　build　stable　and　efficient　mobile　IM　service　that　covers　multimedia　content　sharing　and　corresponds　with　external　services　conveniently.　It　processes　a　message　at　an　average　of　4　milliseconds　and　the　error　rate　is　one　ten　thousandth.