Mitragyna speciosa is a narcotic plant but with specific medicinal importance. The main components of the leaves of M. speciosa are indole alkaloids. Previous scientific researches have shown that the alkaloidal extracts possess very potent anti-inflammatory, analgesic and opioid properties. The three most abundant indoles are mitragynine, paynanthine and speciogynine – the first two of which appear to be unique to this species. All these compounds were obtained from classical organic solvent (diethyl acetate, dichloromethane or methanol) extraction. In this research programme, supercritical fluid extraction (SFE) of M. speciosa was performed. An optimal condition of supercritical fluid extraction was developed using an analytical-scale SFE system. The conventional extraction methods were conducted in parallel for comparison. CO2 extract of M.speciosa has never been studied yet and CO2 was chosen as the media of extraction because it is non-toxic and environmentally safe to prepare and use.