Abstract: Decaffeinating test of green tea concentrative liquid was carried out using supercritical CO₂. The effect of concentrative liquid consistence, operating pressure, operating temperature and extracting time on decaffeination rate was investigated by using orthogonal experiments. The results showed that great majority of caffeine in green tea concentrative liquid could be removed with supercritical CO₂. A new method of processing decaffeinated tea concentrative liquid or instant tea was presented through the experiment of continuous extraction.