Abstract: Based on the daily and hourly meteorological observation data from conventional and traffic meteorological stations from December to February of the following year during 2018—2020,the diurnal variation characteristics and correlation of the monthly average road surface minimum temperature and the ground surface minimum temperature in winter were analyzed by using statistical linear trend correlation method,and the correlation equations between the maximum and minimum road surface temperature and the maximum and minimum ground surface temperature at four stations in winter were established,in order to provide a reference for fine forecasting service of road surface temperature.The results showed that the time when the monthly average road surface minimum temperature and ground surface minimum temperature reached the minimum and maximum values at the four stations of the Minhe to Xining section of Beijing-Tibet expressway in winter were not exactly identical.The sunrise/sunset variation rate of the average ground surface minimum temperature was higher than that of the average road surface minimum temperature,and the variation range of the average ground surface minimum temperature was larger than that of the road surface minimum temperature.The maximum value of average ground minimum temperature is 1～2 h ahead of the maximum value of average road minimum temperature.In general,the hourly ground surface minimum temperature of conventional meteorological observation stations is less than 0 ℃ for 15 to 18 h,and the hourly road surface minimum temperature of traffic meteorological observation stations is less than 0 ℃ for 8 to 22 h.The correlation equations between the maximum and minimum surface temperatures at Chaoyang station,Hanzhuang station,Gaomiaoqiao station and Laoyaxia station established by statistical method have good practical application value and the accuracy of test prediction is high.