Recent　research　found　that　stress　state　and　relative　density　could　influence　internal　instability　significantly,　however,　current　internal　stability　criteria　were　material-specific,　and　the　effect　of　stress　and　density　were　not　accounted　for.　Furthermore,　current　criteria　were　drawn　from　the　dense　soils,　which　could　lead　to　unconservative　assessments　of　loose　soils.　Because　of　this,　this　paper　proposes　a　theoretical　internal　stability　classification　chart　with　considerations　of　soil　density　and　applied　stress.　Based　on　soil　fabric　and　force　transmission,　a　texture　triangle　chart　for　three-component　mixtures　made　up　of　coarse　grains,　fine　grains,　and　voids　was　proposed　through　theoretical　analysis　of　the　void　filling　mechanism　in　coarse　grains.　The　proposed　chart　demarcated　the　boundary　between　internally　stable　and　unstable　granular　soils　and　the　boundary　between　suffusion　and　suffosion　phenomena　for　internally　unstable　granular　soils.　The　classification　chart　relied　on　identifications　of　maximum　and　minimum　porosities　that　coarse　grains,　fine　grains,　and　coarse-fine　mixtures　may　attain.　The　internal　stability　of　coarse-fine　mixtures　with　various　densification　levels　could　be　evaluated　by　plotting　their　position　in　the　proposed　texture　triangle　chart.　The　influence　of　applied　stress　on　internal　stability　could　also　be　evaluated　in　this　proposed　chart　by　assessing　the　changes　in　volumetric　strain.