A study is made of Z-I relationships in various types of rain based on 437 raindrop spectra from Hunan and Anhui. It has been found that (1) the statistical results of the Z-I relationships according to rain types appear to be more reasonable than those of any obtained through reflecting factors Z and rain intensities I: (2) Z-I relationships differ in the significance for different kinds of rain and can not be replaced by each other; and (3) Z-I’s in convective precipitation over the provinces show no differences in significance.Finally, discussion is made as to the properties of Z-I’s in various cases of precipitation, the effect of various time intervals (they vary from 5 min. to 30 min. space. ) between sampling raindrop distributions on statistics of the relationships together with the corresponding measurement errors.