We reported a novel and effective strategy to achieve higher continuity at a lower volume fraction of interphase by using compatibilizers in ternary blend consisting of PVDF, PS and HDPE. PVDF-g-PS was synthesized by electron beam radiation induced free radical graft copolymerization reaction and PVDF-gPS was characterized by FTIR, DSC and H-1 NMR. PVDF-g-PS showed effective compatibilization in PVDF/PS binary blend. The phase size of PVDF/PS binary blend was decreased at addition of PVDF-g-PS. For phase morphology development, morphology of uncompatibilized PVDF/PS/HDPE ( 52/6/42 vol%) ternary blend revealed a part of PS droplets situated in PVDF/HDPE interface, the other part was located inside HDPE phase. Whereas, compatibilized blend showed more and more PS migrate to PVDF/HDPE interface. When adding 7% PVDF-g-PS, PS droplets formed into uniform layer self-assembly arrayed at interface, then tri-continuous morphology was formed and continuity of PS phase increased by 32%, ultralow percolation threshold ternary blend was successfully achieved. (C) 2018 Elsevier Ltd. All rights reserved.U