The error of estimates of soil water content in field can be devided into three components,i.e.that of location,ealibration,and instrument.The analysis of variance of measurements at 5 locations in a wheat field represents that location component is the main source of error most of conditions.The contributions of calibration variance and of instrument variance to total variance are relatively high when the error (CV) is low even the instrument variance is at a very low degree(10^-6(cm³/cm³²).The results of the neutron probe measurements are similar to that of the triditional oven dry method,while errors (CV) of the former are smaller than that of the latter.Therefore,this method should be reliable.In addition to easy and fast to be controlled,this method should be accepted as a effective tool for monitoring soil miosture in field conditions.