Abstract:Glycine betaine is an important osmotic regulator in plants. Many plant cells rapidly accumulate glycine betaine under adverse conditions, including low temperature to maintain an osmotic balance. This article provides an overview of the mechanism of improving cold resistance of plant by glycine betaine and its application, including glycine betaine biosynthesis, its protection mechanism under cold stress, the transformation of glycine betaine synthetase genes, and the effect of exogenous glycine betaine on improving cold resistance of plant.