Abstract: Much of the qualitative work on the features of radar echoes and satellite cloud images for the Apr. -Jun. raining periods in South China has not solved the problem of quantitatively predicting precipitation by means of radar echoes. In this paper, layer-by-layer displays of a 713 radar collections in Guangzhou and hourly surface rainfall records, extracted from a quasi-operational experiment for a research project 75-09- 02 in the Pearl River Delta, are used to study the relations of surface rainfall intensity to 1) radar echo intensity, and 2) heights of strong echo tops, for 3 frontal rains. The Z-R relations here is compared with that derived from raindrop spectra by domestic and overseas researchers.