This study was undertaken to optimize the extraction of proanthocyanidins from flowers of Cinnamomum burmannii. The starting raw material, freeze-dried flowers of Cinnamomum burmannii ground and sieved through a 80-mesh sieve, was extracted using acetone-ethanol and the extract was submitted to color development catalyzed by iron salt before measuring the absorbance. Five extraction conditions including extractant concentration, pH, solid-to-solvent ratio, temperature and time were optimized by one-factor-a...