The　development　of　novel　building　blocks　with　sp3-hybridized-carbon-free　conjugated　skeletons　is　important　to　further　advance　and　enrich　nonfullerene　acceptors(NFAs),but　this　remains　a　challenge　due　to　the　lack　of　strategies　to　effectively　modulate　the　aggregation　behavior　of　resulting　NFAs.Herein,two　novel　nitrogen-bridged　octacyclic　ladder-type　heteroarenes　end-capped　with　thiophene　rings(BTPS)or　selenophene　rings(BTPSe)are　designed　and　synthesized　as　the　donor　cores　for　constructing　NFAs(MQX-2　and　MQX-4).It　is　found　that　replacing　the　sulfur　atoms(MQX-2)at　the　outer　positions　of　the　heteroarene　core　with　selenium　atoms(MQX-4)can　effectively　modulate　the　molecular　packing　mode　of　the　NFAs.The　incorporation　of　selenium　atoms　induces　stronger　O…Se　noncovalent　interaction　than　O…S,thus　promoting　the　formation　of　mixed　H/J-type　aggregates　in　MQX-4.Benefiting　from　more　electron　hopping　channels,MQX-4　exhibits　higher　electron　transport(more　than　1-fold　enhancement)and　photovoltaic　properties　compared　to　MQX-2,which　forms　only　H-type　aggregates.