Abstract: IR spectra and high- performance liquid chromatography was applied for the quality and quantity of caffeine in chicory root.The antibacterial property of caffeine extraction in chicory root was tested with a series of fungi and bacteria.Results showed that caffeine retention time was 3.787min, linear relationship was well between mass concentration 25¹25μg /mL ( R2= 0.9995) .Recovery was between 97.9% ¹01.2%.Sample had good stability within 4 hours.Relative standard deviation was less than 1.0%. Under this condition, chicory root caffeine content was 2.14mg /g. The method was simple and rapid in operations and accurate in determination, the method established in this study was favorable for the determination of caffeine in chicory root.Caffeine extraction in chicory root had obvious antibacterial activity on common food contamination bacteria.