A temperature sensitive gel as extraction agent which is a copolymer of N-isopropy-lacrylamide (NIPA) with sodium methacrylate has been synthesized. The influence of amounts of ionic agent and crosslinking agent on the swelling property of the gel have been investigated. We also inspected the swelling behaviour of the gel in different solvents and at the presentee of acid

alkali and salt. The swelling ratio of this new temperature sensitive gel at room temperature in water is obviously greater than those which are reported

and itsrecov-ery property is good.Its absorptivity of water is almost not changed even after the tenth swelling-shrink cycle.