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The soil freeze-thaw phenomenon is one of the most distinguishing peculiarities of the land surface processes over the Qinghai-Tibetan Plateau. By utilizing soil temperature/moisture and air temperature data from the GLDAS-NOAH product, 4 observing networks and 10 meteorological stations over the Qinghai-Tibetan Plateau, the spatio-temporal distribution of the start/end date and the duration of soil freezing and their relationships with air temperature and altitude were investigated with the analytical methods of linear regression model, correlation analysis, sliding t -test and Mann-Kendall test. As a result, the spatial distribution of top-layer soil freeze-thaw processes was characterized by a trend of delaying freezing and advancing thawing from the northwest to the southeast throughout the Qinghai-Tibetan Plateau. Moreover, in the period 1948–2019, the begin date of soil freezing was delayed at a rate of 1.2 d/10a (p-lev <0.0001, R2 = 0.40), and the end date of the soil freezing was advanced at a rate of 0.5 d/10a (p-lev = 0.105, R2 = 0.04). The duration of the soil freeze was shortened with a rate of 2.1 d/10a (p-lev <0.0001, R2 = 0.23) in the southern Changtang but 0.4 d/10a (p-lev <0.0001, R2 = 0.47) in Qinghai and the southern Tibet Plateau. Additionally, the start date of the soil freeze is to be delayed by 2.8 days (p-lev <0.0001, R2 = 0.53), and the end date of the soil freeze is to be advanced by 3.6 (p-lev <0.0001, R2 = 0.61) days as the air temperature rises by 1.0 °C. In the high cold climatological zone on the Qinghai-Tibetan Plateau, there is a trend toward earlier start date of soil freezing by 9.9 days (p-lev <0.0001, R2 = 0.36), and later end date of soil freezing by 14.4 days (p-lev <0.0001, R2 = 0.56) as the altitude increases by 1000.0 m. Furthermore, the seasonal variations of soil temperature and moisture were significantly different from typical strong and weak freezing years, which were defined according to the duration of soil freezing period. These results are of great significance for understanding the soil freeze-thaw process and its variation over the Qinghai-Tibetan Plateau. • The soil freeze-thaw process over the Qinghai-Tibetan Plateau is analyzed by utilizing observing and reanalysis data. • Notable variability of the soil freeze-thaw process was observed at spatio-temporal scales. • The soil freeze-thaw process over the Qinghai-Tibetan Plateau is closely related to the air temperature and altitude. • Soil water and heat vary with intensity of freezing over the Qinghai-Tibetan Plateau. [ABSTRACT FROM AUTHOR]