The soil relative humidity measurements from the agrometeorological automatic station and manual observation of the Juxian Meteorological Bureau at the same time in a natural state of nonirrigation from 21 September 2005 to 18 December 2006 are compared and analyzed by means of the difference contrast, difference probability, and correlation methods. The results show that the measurements from the automatic station are unsatisfactory in the layers of 0-5 cm and 0-10 cm but satisfactory in the layers of 10-20 cm and 40-50 cm. It is concluded that the 0-10 cm sensor parameter must be adjusted and replaced, and the design of the sensor must consider the influence of frozen earth. The variation of 90-100 cm depth data is steady, so it is suggested to cancel the sensors at the two levels of 90-100 cm and 170-180 cm.