Abstract: Based on the observational data from a newgeneration ground-based microwave radiometer with double channels and coantenna developed by Peking University, the distribution characteristics of integral liquid and vapour water content in the atmosphere are analyzed on the conditions of clear air cloud without rain during April to June from 1992 to 1994 in Shijiazhuang of Hebei Province. The results indicate that the liquid water makes up one percent of the total water content in the atmosphere without rain, the liquid water resources in clouds for artificial precipitation are only little part of the total. Therefore, the analysis shows that the conventional method of using water vapour content in the atmosphere to estimate cloud water resources is very overstatement.