Abstract: The local climatic data from 1962 to 2018 in the Eighth Agricultural Division of Xinjiang was used to analyze the freezing beginning period, thawing period and persistent period of frozen earth, and the relationship between the maximum depth variation trend of the frozen earth and the climatic factors. The results indicated that seasonally frozen soil of reclamation area in the Eighth Agricultural Division of Xinjiang was stable from November to March of the next year, and the frozen earth was the deepest in the first and middle ten-day of February; The inclination rate at the freezing beginning period was 1.12 d/10 years, with the linear backward about 6 d; The inclination rate at the thawing period was -1.42 d/10 years, with the linear forward about 8 d; The inclination rate at the persistent period was -1.36 cm/10 years, with the linear shortening about 8 d; The inclination rate of the maximum depth of frozen soil was -8.09 cm/10 years, with the linear decreased by 46 cm. The maximum depth change of frozen soil was significantly correlated with air temperature, rainfall, and snow depth at the same period. For every 1 ℃ increase in air temperature from November to March of the next year, the layer of frozen soil became about 4.0 cm shallower; For every 10 mm increase in precipitation, the layer of frozen soil became about 2.5 cm shallower; For every 1 cm increase in snow depth in January, the layer of frozen soil became about 0.7 cm shallower. The layer of seasonally frozen soil became shallow gradually, and the shortening of the frozen soil period had a direct relation with the climate warming.

Key words: seasonally frozen soil, change characteristics, climatic factor, Eighth Agricultural Division of Xinjiang