Abstract: Based on the daily observation data of thunderstorm in Tongliao National Basic Meteorological Observing Station from 1961 to 2011,climate change characteristics of thunderstorm were analyzed by using mathematical statistics and climatic trend method,furthermore significance test was carried out by using t-test.Results showed that the annual number of thunderstorm days in Tongliao in recent 50 years had a decrease trend generally,and climatic trend rate was-1.04 d per 10 years.The average number of thunderstorm days in Tongliao in recent 10 years was 23.2 d,which was 5 days less than that in former 40 years.The average annual number of thunderstorm days was 27.3 d;the average first-day of thunderstorm was May 10,and the average end-day of thunderstorm was September 27,and there were 142 days between them.Thunderstorm mainly appeared in June,July and August,among them the number of thunderstorm days in June and July accounted for 57% of annual number of thunderstorm days.There was less thunderstorm in November,and there was no thunderstorm from December to March in next year.