[Objective] Molecular distillation technique was applied for the separation and purification of Atractylodes Lancea oil (ALO) to increase the yield of atractylodin. [Methods] Atractylodes Lancea oil prepared with supercritical extraction was refined by molecular distillation technique. The optimum refining conditions were selected by uniform design containing two factors of temperature and vacuum and five levels. The content of atractylodin from refined Atractylodes Lancea oil was measured and the remainder...