Using the precipitation data of 18 weather stations in the southeastern Guizhou Province from 1960 to 2000, the temporal and spatial distribution, variation regularities, and influencing factors of heavy rains are analyzed statistically. The results indicate that there is notable interdecadal variation in heavy rainfall over the southeastern Guizhou Province with a quasi-15 year period and the same phase with precipitation variation in the whole Guizhou Province and the middle and lower reaches of the Changjiang River; there are two high-occurrence centers; heavy rainfall occurs more frequently in the evenings; heavy rains are disturbed highly unevenly, mostly local rainfall, which are related to the special topography in the southeastern Guizhou Province. The climatic causes are also discussed.