Using the data of thunderstorm days recorded by 74 ground meteorological observatories in Hunan province from 1961 to 2010,the climatic characteristics of thunderstorms during the past 50 years were analyzed by means of mathematical statistics,wavelet analysis and Mann-Kendall test.The results show that there is a deceasing trend of thunderstorm days from the north to the south,with the highest number of thunderstorm days in the mountainous region of the south for 65.38 d/a,and the lowest number of thunderstorm days in the plain of the north for 21.92 d/a.The distribution of average monthly thunderstorm days are observed to be a single peak curve,with the peak period appear in March to September.The oscillation periods of 8 years,16 years,24 years and 30 years are found in the number of average annual thunderstorm days in Hunan,with most remarkable period being 8 years.The climatic difference between the periods with more or less thunderstorm days appears as the position of westward move of the subtropical high over the Western Pacific,as well as the position and strength of short-wave trough of Tibetan Plateau.