Although investigations of characteristic quantities of raindrop microwave radiation have been documented,the subject needs to be further explored. This article proposes astatistical medel for the relations Z-M,M-I and k-M established by analyzing the raindrop sizedistribution in a rainfall event,Compared with some theoretical medels and relevant datasetsreporied, significant results have been achieved and are of useful reference both in theoretical andpractical aspects of weather prediction.