Efforts for the retrieval of soil moisture data using satellites are continuing, but there is a lack of reference data that can represent the characteristics of a watershed. In this study, weighted average in situ soil moisture was estimated and the calibrated CRNP soil moisture was validated through comparison with rainfall events. The weighted average in situ soil moisture adequately represented that of all stations. The corrected neutron intensity was less affected by air pressure and humidity than the raw data, and the standard deviation decreased from 96.22 cph to 76.25 cph. Additional correction for the mountainous terrain will be possible if data are accumulated, and the CRNP soil moisture can be used as reference data for soil moisture retrieval using satellite data and as basic data for national water management. Keywords: Soil Moisture, Cosmic-ray, FDR, Weighted Average Soil Moisture