Abstract: The relationship between frost injury, low temperature and population of ice nucleation active bacteria on crop leaves are studied by means of radiation-cabinet. The results indicate that the Logistic equation can show the relationship between frost injury and low temperature only under the conditions of a few or even no ice nucleation active bacteria. But Richards equation can describe well the relationship between these three factors under various conditions of ice nucleation active bacteria. Furthermore, the applications of this relationship to frost injury indexes, frost injury prediction, and frost preventing method are discussed.