Abstract: In order to carry out an experiment on frost prevention technology in apple florescence effectively, the authors used the temperature and wind speed data obtained from the apple orchard gradient meteorological tower in Luochuan, adopted mathematical statistics method to analyze the characteristics of nighttime inversion on the surface layer. The results showed that: Luochuan had basic conditions for carrying out frost prevention when the radiation was cool in spring, with long lasting period, small temperature difference and low wind speed. The arisen time of inversion was closely related to the time of sunrise and sunset, the inversion formed after sunset, and disappeared after sunrise. The average intensity of inversion was 0.7-0.8℃, the maximum value appeared at midnight in winter, and before dawn in spring (April to May). The mean intensity of inversion in the surface layer could be over 2℃ and the maximum value could reach 4℃ when the radiation frost occurred in spring. The inversion would not form when the night was cloudy or rainy or the wind speed was greater than 2.5 m/s at night in spring.