The data of production of apple-pear from 1949 to 2010 and the meteorological data of major apple-pear production area in Yanbian area of Jilin Province were collected and analyzed.The freezing injury indexes of apple-pear were studied using the principal component analysis,the correlation coefficient calculations and other methods of mathematical statistics.The research results showed that -18℃ was the critical temperature for apple-pear winter freezing injury.According to the critical temperature,the extreme minimum temperature（below -18 ℃ from December to February） continuous days,extreme minimum temperature,maximum cooling extent and harmful chilling accumulation were used as the disaster-inducing factors.The comprehensive freezing injury indexes of apple-pear were obtained by using the method of principal component superposition of the hazard.The grades of freezing injury could be divided into four grades: light freezing injury,medium freezing injury,severe freezing injury and extremely severe freezing injury.