Abstract: According to actual observation data of temperature in mountain area and the investigation results of loquat yield reduction caused by the low temperature injury in Fujian province, the critical temperature of loquat yield reduction caused by the low temperature injury was determined as 1.0℃(inside thermometer screen), and then by comparing the temperature data of township automatic weather station and city county meteorological station, the actual critical temperature of low temperature injury was determined as 3.0℃.According to the daily climatic data of winter from 1992 to 2009 and relative meteorological yield of loquat in Fujian, the disaster inducing factors for low temperature injury of loquat was determined, the factors included extreme minimum temperature, the sum of daily numbers for ≤3.0℃, the maximum sustained days of low temperature injury for ≤3.0℃, and the accumulated temperature for ≤3.0℃. By using the method of principal component analysis to simplify comprehensively four disaster inducing factors, the integrated climatic index of low temperature injury evaluation of loquat was obtained, and the index classification was determined by combining relative meteorological yield with the index. The trial calculation in Putian showed that the integrated climatic index of low temperature injury was significantly negatively correlated with the relative meteorological yield of loquat（P＜0.05）. The results had practical reference value for evaluation low temperature injury degree of loquat in Fujian province.

Key words:  Loquat, Low temperature injury, Critical temperature, Relative meteorological yield, Integrated climatic index