Nonlinear trend and periodic characteristics of monthly mean precipitation in each region over Guangdong Province from Jan to Dec were studied

by using the methods of multiple variables regression and variance analysis. The results are: The trend in all regions is generally less significant than its period. Specially there are 2 or 3 years period characters in summer months

and 5 or large than 5 years period in spring and autumn months

but in winter months the characters of period are weaker.