Based on daily and monthly temperature records from 1957 to 2001 of China，using climate extreme detecting method based on average and median，we have analyzed the transition and distribution of frequency of temperature extremes.The results indicate that while the average number of extreme high temperature events per year has been increased in the last 50 years,the extreme low temperature events decreased.Except for some stations located in southwest China，the frequency of extreme low temperature events in most regions over China decreased.The spatial pattern of transition of frequency of extreme high temperature events showed decreased in southeast coastal regions and increase in inland regions.