In　order　to　improve　the　synchronization　efficiency　of　the　high-capacity　agricultural　spatial　data　in　the　wireless　network,　a　new　4-tuple　synchronization　model　(MCOD)　is　proposed.　The　model　represents　the　relationships　among　the　four　elements,　such　as　the　atomic　change　types,　synchronized　data,　synchronized　operations　and　synchronized　metadata.　To　establish　the　model,　a　new　typology　with　11　atomic　change　types　of　the　agricultural　features　is　firstly　proposed.　Based　on　the　typology,　the　corresponding　synchronized　data　and　operation　of　every　change　type　are　given.　An　instance　of　the　model　is　realized　by　establishing　the　relationships　among　the　change　types,　corresponding　data　and　operation　of　all　changed　agricultural　features.　At　last,　the　corresponding　relation　between　elements　of　the　synchronization　model　and　XML　model　is　given.　Thus,　the　model　can　be　automatically　described　as　XML　data　files　which　make　it　perfect　for　transferring　data　between　servers　and　mobile　clients.