In　engineering　constructions,　the　backfill　behind　retaining　walls　is　usually　narrow,　and　its　boundary　conditions　are　asymmetric　due　to　the　space　limitation.　When　the　retaining　wall　rotates　about　the　bottom,　the　direction　of　the　principal　stress　also　rotates　due　to　the　granular　properties　of　soil　and　the　multiple　interfaces　friction.　Such　phenomenon　is　more　significant　in　narrow　backfill,　however,　there　are　few　studies　about　this.　The　finite　element　method　analysis　is　able　to　demonstrate　how　the　failure　mode　of　narrow　backfill　and　the　rotation　of　principal　stress　are　affected　by　the　backfill　geometry　and　interfaces　friction.　Theoretical　analysis　is　employed　here　to　calculate　the　principal　stress　rotation　angle　and　lateral　pressure　coefficient　of　the　interface　element.　Similarly,　active　earth　pressure　of　narrow　cohesionless　backfill　against　inclined　rigid　walls　rotating　about　the　bottom,　considering　principal　stress　rotation　and　uniform　load　on　the　ground,　is　derived　by　differential　element　limit　equilibrium,　which,　upon　comparison　with　methods　used　in　previous　studies,　is　suitable　for　the　asymmetric　inclined　boundaries　and　improves　the　scope　and　accuracy　of　calculation.　Parametric　studies　herein　show　that　increasing　the　new　structure　inclination　and　decreasing　its　friction　will　reduce　the　interference　in　the　existing　structure.　©　2020　American　Society　of　Civil　Engineers.