The decocted extract of Uncariae Ramulus et Uncus, for which prolonged boiling is presumed to reduce its activities, was extracted with n-hexane-chloroform (5: 1) and methanol consecutively. The patterns of each organic solvent extract were analysed with thinlayer chromatography (TLC) by several solvent systems using the Dual-wavelength TLC Scanner. No clear difference in the patterns was evident in any of the 10-120 min decocted extracts. The comparison of patterns of the chromatograms however revealed some new informations.