The daily rainfall data at two meteorological stations located at an urban site and an open area of the urban forest ecological site from 1988 to 2003 were collected. The author analyzed the rainy days and the daily maximum rainfall of each month, and rainstorms as well in past 16 years. The results showed that the normals of annual rainy days in the urban forest area were 7.3 days less than that in the urban site. During the period of November to March, a daily maximum rainfall could be heavy rain, moreover the percentage of moderate rain days in the forest area was higher than that in the urban area. However, the percentage of small rain days in the urban forest area was lower than that in the urban site. The rainstorm could happen during April to October of each year and at summer in the main, and there was no significant difference at the frequency and rainfall of rainstorm between two sites.