To better understand the influence of sea surface temperature (SST) on tropical cyclones rapidly intensifying, the characteristics of rapid changes in sea surface temperature and intensity of tropical cyclones in the western North Pacific during 1979−2019 were statistically analyzed using the tropical cyclones best track data compiled by the Shanghai Typhoon Research Institute of the China Meteorological Administration and the sea surface temperature data provided by European Centre for Medium-Range Weather Forecasts. The results indicate the following: (1) About 90% of the rapid intensification of tropical cyclones occurred in summer and autumn, accounting for 32.8% and 56.4% of the total number of rapid intensification respectively. Most tropical cyclones are dominated by rapid intensification across one intensity level, rapid intensification from a severe tropical storm to a typhoon and rapid intensification from a typhoon to a severe typhoon are the two conditions that occur more frequently. (2) The SST conditions greater than 28℃ in summer and 27.5℃ in autumn are conducive to the rapid intensification of tropical cyclones. Lower intensity of tropical cyclones require higher SST (> 29℃) for rapid intensification. The faster translation speed of tropical cyclones is conducive to maintaining high SST environment at its center. (3) When the time variation of SST is within ±0.2℃/(6 h), the horizontal spatial gradient is less than 0.4℃/(°), which is the favorable condition for the rapid intensification of tropical cyclone; the stronger the tropical cyclone is, the more stable the SST environment is needed. (4) When tropical cyclone is a severe tropical storm or above, it is better to judge whether rapid intensification occurs by using only the SST conditions. This work quantifies the SST environment conducive to tropical cyclone intensification and provides a technical reference for quantitative prediction of tropical cyclone intensity evolution based on SST.