A gasified-solvent-flow-extraction method has been developed for the microextraction of volatile constituents from powdered samples. A small amount (1-50 mg) of sample is inserted into a glass tube and heated to a preset temperature. The volatile constituents immediately vaporized by heat are transferred by a gasified solvent to a cooling tube where they are recovered as a solution. On this solution, gas chromatography analysis can be carried out directly without concentration and cleanup procedure. Liquid chromatography and thin layer chromatography can also be carried out on the solution. This method was applyed to the quantitative analysis of the volatile constituents of crude drugs. The optimization procedure for conducting this method is discussed.