Human activity increases the frequency and intensity of heavy rainfall and significantly changes the rainstorm characteristics. Clarifying the impact of urbanization on the characteristics of rainstorm is of great significance for urban flood control and disaster reduction. Based on the 15-minute precipitation data of 11 rainfall stations?in different administrative regions from 2006 to 2019, this study took Guangzhou City, Guangdong Province, China as an example, analyzed the response of rainstorm characteristics to urbanization in humid areas from seven aspects: rainfall amount, intensity, frequency, number of days, type, ratio of peak and peak coefficient. The results indicate that: (1) The amount, number of days, intensity and frequency of rainstorm in the area with higher urbanization rate are higher than those in the area with lower one, while the frequency of rainstorm is opposite in temporal variability. (2) The impact of urbanization on rainstorm patterns was not significant. The distribution of rainfall patterns across districts in Guangzhou were not notable, and most of them were single-peak patterns, around 63% of the total. (3) The proportion of rainstorm peaks does not show a significant response to urbanization, and it has a negative correlation with duration. Short-duration rainstorms are dominated by peak rainfall, while in long-duration and ultra-long-duration rainstorm events, the duration is the main factor affecting rainfall changes. (4) The influence of urbanization on the peak coefficient of short-duration and ultra-long-duration rainstorms in Guangzhou is significant, with the areas of higher urbanization rates having noticeably higher coefficients than those of lower urbanization rates. Additionally, most of Guangzhou's rainstorm patterns are of the early-stage concentrated type with a single peak, but for areas with higher urbanization rates, the ultra-long-duration rainstorms are mostly of the late-stage concentrated type, which requires special attention.