A　macro-micro　integrated　land　use　change　model,　Grey-Cellular　automata　(CA)　-Multi-Criterion　Decision-Making　(MCDM)-Geographic　Information　System　(GIS)　based　model　(GCMG　for　short)　which　can　simulate　human　decision　making　process　was　proposed.　The　GCMG　model　borrows　the　theoretical　hypothesis　of　CLUE-S　model　which　supposes　that　regional　land　use　change　is　driven　by　its　land　use　requirement　and　the　land　use　distribution　is　in　dynamic　balance　with　land　use　demands　and　regional　natural　resources　and　socio-economic　conditions.　The　GCMG　model　consists　of　both　non-spatial　and　spatial　part.　The　non-spatial　part,　so　called　macro　model,　calculates　the　changes　of　land　use　demand　in　the　future　based　on　experiential　relationship　of　land　use　and　its　dominating　drivers　using　the　grey　model.　The　spatial　part,　also　called　micro　model,　completes　the　land　use　allocation　process　whose　total　quantity　is　calculated　by　the　non-spatial　part　with　a　combined　method　of　MCDM,　GIS　and　CA　model.　In　the　spatial　part,　firstly　MCDM　method　was　used　to　simulate　the　human　decision　making　process　for　land　use　change　considering　socio-economic　and　bio-physical　conditions;　the　results　of　which　was　brought　into　conversion　rule　of　CA　model;　and　the　integration　was　finally　implemented　in　GIS　to　model　the　land　use　allocation.　To　illustrate　the　functioning　of　GCMG　model　and　its　validation,　it　is　applied　in　Longhai　County　to　simulate　land　use　change　in　2010.　As　one　of　the　typical　counties　at　coastal　area　of　Fujian　Province,　great　changes　in　land　use　have　taken　place　in　Longhai　County　over　the　past　decades,　including　the　garden　plots　expansion,　town　land　for　urban　and　rural　housing,　and　land　for　industrial　and　mining　purpose.　Firstly　the　GCMG　simulation　results　are　compared　with　map　of　the　actual　distribution　of　land　use　in　2000　for　validation.　The　Kappa　equals　to　0.93　in　the　simulation　at　10　m　×　10　m　grid　level　and　has　gained　satisfactory　results.　Then　the　validated　model　is　applied　to　simulate　the　land　use　conversion　probabilities　under　different　decision-making　scenarios.　The　results　show　that　the　basic　farmland　protection　policy　will　determine　the　future　land　use　change　pattern.　The　application　of　GCMG　model　indicated　that　it　can　both　simulate　the　land　use　demand　at　macro　level　and　land　suitability　at　micro　level,　thus　possessing　the　ability　of　studying　the　multi-level　land　use　system.