Abstract: This paper introduces that entrainers used in supercritical fluid extraction (SCFE)operation theory and choice principle of entrainers are concluded and analyzed, and entrainers applied in extracting tobacco available components, such as nicotine and essential oils, are emphatically discussed.and seek for excellent supercritical fluids &suitable entrainers aim at extracting tobacco available components, improving selection &adding up yield.It will become key-point question of studying on tobacco available components using SCFE.