There are a lot of valuable aromatic components in light cycle oil (LCO). Among them, 2,6-dimethylnaphthalene (2,6-DMNA) is focused as the elementary raw material for engineering plastic (PEN plastic) and polymer liquid crystal etc. This study was experimentally investigated to separate and recover a mixture of dimethylnaphthalene (DMNA) isomers in the LCO by distillation-extraction combination as a pretreatment for the separation and purification of 2,6-DMNA in the LCO. The distillation-extraction combination of this study for the separation and recovery of DMNA in the LCO was effective.