AIM: To study the determination of dl-tetrahydropalmatine (THP) in Chi nese traditional patent medicines by TLC-Scanning from the viewpoint of the pro cess control of manufacture. METHODS: To select the 5 kinds of representative drugs and its prep arations contained, THP was extracted with solvent method. The mobile phase contains diethylamine. THP w as separated with high-efficiency silica gel plate or handcrafted silica gel p late. Iodine was used for chronogenic agent and fluorescence defectiion for dete rmination. TLC-Scanning results were compared with HPLC. RESULTS: The method is practicable, the result is correlative with the HPLC. CONCLUSION: TLC-Scanning is fit for the quality control of the Chi nese traditional patent medicine in the process of manufacture.