NOVELTY - Method for preparing medicinal raw material involves crushing e.g. Hibiscus manihot root, or whole H.manihot plant, soaking in deionized water, filtering, soaking filtered residue in deionized water, filtering combining all the filtrates to obtain solution A, drying remaining raw material, soaking in ethanol, filtering, recovering ethanol, soaking filtered residue in ethanol, filtering combining all the filtrates to obtain solution B, mixing solution A and solution B, adding e.g. butanol, standing, filtering and concentrating.    USE - Method useful for preparing medicinal raw material, which is useful for preparing healthcare food, and medicine in form of tablet, dispersible tablet, soft capsule, microcapsule, granule, pill, pellet, powder, dropping pill, sustained release formulations, controlled release formulation, gastrointestinal targeting agent, oral liquid formulation or injection for providing hypnotic and sedative effect. (all claimed).    ADVANTAGE - The prepared medicinal raw material causes only minimal side effects.    DETAILED DESCRIPTION - Method for preparing medicinal raw material involves (a) crushing Hibiscus manihot root, leaf, stem and flower or whole H.manihot plant, adding 10 times deionized water, soaking for 48 hours, filtering with Buchner funnel to obtain aqueous filtrate, adding deionized water to filtered residue, repeating soaking and filtering process for 4-5 times to obtain mixed filtrates (f1), combining mixed filtrates (f1) with aqueous filtrate to obtain solution A, (b) drying remaining raw material obtained in step (a) at low temperature using vacuum drying machine to obtain dried material, adding 10 times ethanol to dried material, extracting for 24 hours, filtering with Buchner funnel to obtain ethanol filtrate, performing vacuum distillation at 40-50 degrees C to recover ethanol, adding ethanol to filtered residue, repeating soaking and filtering process for 4-5 times to obtain mixed filtrates (f2), combining mixed filtrates (f2) with ethanol filtrate to obtain solution B, and (c) mixing solution A obtained in step (a) and solution B obtained in step (b) together to obtain mixed solution, adding 0.5-0.8 times petroleum ether, 0.2-0.4 times ethyl acetate and 0.6 times butanol to mixed solution, mixing evenly, adding resveratrol to obtain final concentration of 250 mu g/ml, mixing evenly, standing at 5-10 degrees C for 40-48 hours, filtering with Buchner funnel to obtain filtrate, concentrating under reduced pressure by performing distillation to obtain concentrate.