The 46-year’s hourly observational information from 1956—2001 at Guangzhou Baiyun Airport is used to statistically analyzed the thunderstorm climatic characteristics and the wavelet transform is conducted. The results are obtained as follows: Year-averaged days of thunderstorm emergence at Baiyun Airport is 75.4 days. The early thunderstorm day in a year is generally on March 1, and the last thunderstorm day is generally on October 14. It is possible to occur a thunderstorm in any month a year, but occurring frequency of thunderstorm is much concentrated in April—September, the peak is in August and the minimum is in December. There are conspicuous seasonal and daily variations the thunderstorm. The variation period thunderstorm climatology has a 9—12 years, and the frequency is gradually decreased in the last 46 years.