Abstract:Operational tests are conducted for measurements from 20 soilmoisture automatic stations which were built in 2010 in Yunnan, based on the related operational verification standards. Among the 20 automatic stations, 17 passed the operational tests. In order to assess the data quality of the passed stations, a comparative analysis is made between manual and automatic observation data. Since verification was conducted mostly during rainy season, the standard deviations of observation samples are usually small, which leads to large errors during dry season afterwards between manual and automatic observation. The absolute errors of volumetric soil water are converted into soil relative humidity errors, and it is found that the number of error values with soil relative humidity above 10% accounts for 241% of total number in effective verifications; and the number of ones under 6% make up only 426% of total number. It is considered that the current evaluation criteria of the operational tests for soilmoisture automatic stations are worth of further discussion and argument.