Abstract: Many researches on molecular mechanism of chilling tolerance have been reported in these years. In this paper, we give a review of four aspects. The chilling sensitivity of plants can be regulated by the level of unsaturated fatty acids in membrane lipids, which could be attained by controlling the action of glycerol-3-phosphate acyltransferase and acyl_lipid desaturases. The chilling tolerance can be strengthened, by transfering some genes encoding antioxidant enzymes, such as SOD, APX, CAT and GR. Some researches demonstrated: ABA is not only an important stress signal of low temperature, but also regulates the expression of many genes under low temperature, Ca2+ is a major second messenger, protein kinases also take part in the signal transduction under low temperature in plant. The chilling_induced proteins or enzymes involve dehydrate proteins and heat-stable proteins.