This　study　investigates　the　transient　modeling　of　regional　rainfall-triggered　shallow　landslides　in　unsaturated　soil　using　the　Richards　equation.　To　model　shallow　landslides　within　a　distributed　regional-scale　framework,　infinite　slope　stability　analysis　coupled　with　the　hydrological　model　with　consideration　of　the　fluctuation　of　time-dependent　pore　water　pressure　and　the　soil-water　characteristic　curve　proposed　by　van　Genuchten　was　developed.　The　validity　of　the　proposed　model　is　established　through　several　test　problems　by　comparing　the　numerical　results　with　the　analytical　solutions.　A　new　procedure　to　set　up　wide-range　shallow　landslide　analysis　and　to　integrate　regional　distribution　variations　for　input　data　such　as　geology,　groundwater　level,　hydrogeological　characteristics,　and　rainfall　intensity　and　duration　was　presented.　The　results　obtained　demonstrate　that　the　computed　distribution　of　the　safety　factor　is　consistent　with　the　distribution　of　actual　landslides.　In　addition,　the　fluctuation　of　pore　water　pressure　in　unsaturated　soil　dominates　the　stability　of　landslides　during　typhoons　accompanied　by　heavy　rainfall.　The　findings　observed　in　this　study　are　a　fundamental　contribution　to　environmental　effects　for　landslides　in　areas　with　higher　occurrence　and　vulnerability　to　extreme　precipitation.