Caffeine was found in a number of plants and beverages, the content of caffeine was determined using a sensitive high-performance liquid chromatographic method. The separation was achieved on a liquid chromatographic reversed-phase 5C18 column with a mobile phase of 0.1M sodium borate huller (pH 6.4)-methanol (72:28, v/v) at a flow rate of 1mL/min. The eluted caffeine was detected with 270nm. The limit of detection of caffeine was 10ng/mL. These results suggested among the beverages, the coffee had the greatest caffeine content (503.58±1.28μg/mL), and among tea and coffee products, coffee had greater caffeine content (39.8±0.3 mg/g).