Based　on　the　SuperMap　GIS,　an　agricultural　land　suitability　assessment　system　(ALSAS)　for　Zhangzhou　Area　in　Fujian　Province　was　developed　using　the　vector　data　model　and　the　intersecting　result　of　evaluation　factors　as　the　evaluating　unit.　The　selection　of　evaluation　crop　and　evaluation　factors,　determination　of　target　gradation　and　weights　can　all　be　done　by　the　user.　The　user　can　exclude　the　land　area　that　do　not　include　in　the　evaluating　area.　The　system　makes　itself　more　convenient　by　storing　the　crop　ecological　index　database　in　practice.　It　can　deal　with　all　kinds　of　data　timely,　and　has　other　functions　related　to　crop　assessment　such　as　analysis　and　statistics.　It　can　serve　as　a　guideline　for　introducing　new　kind　of　crop　and　agriculture　structure　adjustment.　From　the　practice　of　developing　the　ALSAS,　its　implementation　process　and　methods　based　on　GIS　were　discussed.