Herein,　we　report　a　new　n-type　ladder-type　conjugated　polymer,　dichlorinated　poly(benzimidazoanthradiisoquinolinedione)　(Cl2-BAL),　that　possesses　a　slightly　twisted　polymer　backbone　and　a　preferred　edge-on　orientation.　Upon　n-doping,　its　maximum　electrical　conductivity　and　power　factor　in　thermoelectric　devices　reached　1.1　±　0.07　S　cm-1　and　3.52　±　0.37　μW　m-1　K-2,　respectively,　and　is　almost　on　par　with　the　best　performing　ladder-type　conjugated　polymer　BBL.　As　compared　to　our　previously　reported　tetrachlorinated　analogue　Cl4-BAL,　our　results　demonstrate　that　the　chlorine　atoms　can　influence　not　only　the　torsion　angle　but　also　the　orientation　and　π-π　stacking,　which　in　turn　dramatically　affects　its　performance.　©　2023　American　Chemical　Society