The present paper discusses mainly characteristics of one metre thermome-try with an analysis of the major interference factors, especially the effect of annual variation caused by periodical change in the intensisty of solar radiation on the shallow-layer thermometry and its correction. The effects of differences in such thermal physical properties as thermal conductivities and thermal diffusi-tivities on geothermal field are also dealt with. Finally, some problems worth mentioning in sorting out and interpreting thermometric data are tackled, with the example of Yiushan geothermal area given to illustrate the effectiveness of one metre thermo metry.