Cinnamon is one of the world's oldest spices that is also widely used as medicine for antimicrobe, anti-inflammation, and immune stimulant to now developed as an antidiabetic herbal medicine. Among its bioactive contents, the coumarin must have been controlled; since of its toxicities. Therefore, in this study aimed to reduce the amount of coumarin in the extracts by chloroform preextraction to dried powdered cinnamons and determine their glucose binding capacity. The extractions were used two methods by water infusion and ethanol soxhletation. To measure the coumarin's was used validated thin-layer chromatography (TLC)-densitometry, while for the chemical profiling of the extract was examined with liquid chromatography–mass spectrometry. The activity antidiabetic of the extracts was obtained by glucose binding. The TLC-densitometry method has been validated with silica gel 60F254 and n-hexane: ethyl acetate (8:2, v/v) systems. The coumarin's spot was observed at a wavelength of 285 nm on retention factor (Rf) 0.33, with tailings factor 1. The intraday and interday linearities tests showed a linear response result. The recovery value, coefficient of variation, and detection and a quantitation limit were met the standard requirements, respectively. Moreover, the results were observed (1) the solvent preextraction may reduce the coumarin content, (2) the coumarin content in the ethanol extract was higher than in the infusion, and (3) the preextraction solvents would reduce the glucose-binding capacity in ethanol and water cinnamomi's extract. These results may be developed further and applied for producing cinnamon's free coumarin extracts.