Abstract: Based on the data of Xiamen national meteorological station from,1973 to 2021,the variationcharacteristics of temperature and heat resources were analyzed by climate trend rate,cumulative anom-aly method and Mann-Kendall mutation test. The results showed that the annual average temperature inXiamen rose significantly at an average rate of 0.478 ℃ /10 a,and the temperature rise was most obvi-ous in spring. The increase rate of the average maximum temperature ( 0.515 ℃ /10 a) was significantlyhigher than that of the average minimum temperature ( 0.285 ℃ /10 a) . The upward trend of the activeaccumulated temperature was also observed. The increase rates of annual active accumulated tempera-ture,≥10 ℃,≥15 ℃ and ≥20 ℃ accumulated temperatures were 175.57,246.07,229.72 and268.92 ℃ /10 a,respectively. The abrupt change of active accumulated temperature from cold to warmoccurred during 1997—2000. Heat resources can effectively improve the yield and quality of thermophi-lic crops,but may bring about meteorological disasters such as pests and diseases and aggravate the ur-ban heat island effect. Close-