Abstract: Based on the data observed with the manual frozen soil apparatus (MFSA) and the temperature-measuring automatic frozen soil apparatus (TMMFSA) from December 2018 to March 2020 at four national surface meteorological stations i.e.Kazuo, Shenyang, Liaoyang, and Manzhouli, the freezing point obtained from MFSA and soil temperature measured with TMMFSA were compared.The results show that the freezing point temperature from MFSA was generally consistent with 0℃ with some small differences.At 0-35 cm soil depth, soil temperature corresponding to the freezing point was between -2 to 6℃ with a jumping change.Below 35 cm soil depth, soil temperature corresponding to the freezing point ranged from -0.5 to 1℃, and the mean temperature corresponding to the freezing point in the melting process was higher than that in the freezing process.The completely melting time observed with MFSA was later than that when the 0℃ lines observed by TMMFSA disappeared completely.The essence of artificially frozen soil observation is to obtain the position of soil temperature of 0℃.Under the same temperature conditions, there is no obvious difference between freezing and melting state in the inner pipe of the frozen soil observation instrument filled with water from different stations.The freezing process of the inner pipe of MFSA was closely related to the temperature and duration of the persistent freezing.Specifically, slow change of soil temperature in the deep layer causes the increase of duration of freezing and melting of water in the pipe.As a contact temperature measuring device, reducing the time delay caused by external reasons is very important to improve its sensitivity.It is suggested that the metal outer tube with less temperature lag effect should be used in TMMFSA, and the soil temperature with high spatio-temporal resolution obtained by TMMFSA should be applied to business.More importantly, soil temperature data measured by TMMFSA can provide sufficient data to support the study of the characteristics of soil temperature change and the heat exchange between soil and atmosphere.