Abstract:In the last 3 decades, antifreeze proteins (AFPs) have been studied in overwintering insects, polar fish, then in plant materials. The studies in fish AFPs were more comprehensive and systematic. Four groups of AFPs are indentified in the polar fish: AFGPs (antifreeze glycoproteins), AFPⅠ, AFPⅡ and AFP m. Two new AFPs, THP26/27 (in Tenebrio molitor), DAFP-1/-2 (in Dendroides canadensis), are purified from insects. Recently, five AFPs in plants are purified: Sd67 (in Solanum dulcamara ), three antiftmgal proteins ( in Secale cereale ) and afp ( in Ammonpiptanthus mongolicus ). Their THA ( thermal hysteresis activity) is lower than that of fish and insect AFPs. Plant AFPs may have four fimctions in the antifreeze process of plant: ( 1 ) lowering the freezing point; (2) inhibiting ice-recrystallization; ( 3 ) modifying ice morphology; (4) regulating the supercooling state of protoplasm. And it is the last one that may be the key role of AFPs to beneficiate the plant undergoing an antifreeze physiological process.