For the quality control of crude drug drink preparations, methods for identification of cinnamon components and quantitative determination of cinnamic acid were established. Cinnamon components were identified by TLC with benzene/ethyl acetate (1:1, v/v) on silica gel plate by spraying p-anisaldehyde-sulfuric acid. Cinnamic acid contents were determined at UV 280 nm by HPLC on $mu$-Bondapak Cls column with acetonitrile/water/acetic acid (40:60:2, v/v). Recoveries of cinnamic acid in three crude drug drink preparations were between 84.1-90.2% compared to the content of the cinnamon extract.