With due attention to importance of climate change and natural ecosystem sensibility of the study area, in this research have been studied the probable climatic departure from normal and the existence of trend in climatic time series is detected by statistical tests. The first on the basis of rank- method Mann Kendal, it is tried to identify of changes and then recognize their type and time. The results which are provided of data analysis by this method show that the most changes started as abrupt and it is known that these changes belonged to both type of trend and oscillation. The minimum temperature shows a positive trend and the maximum temperature shows a negative trend in the most of selected stations. Therefore, it seems the range of temperature has reduced during the study period. Also, the percentage of changes on winter and summer has been more than spring and autumn situation. Eventually, there aren’t any coincident between the selected stations for purposes of changes beginning.
Keywords: South coasts of Caspian sea, Climate change, Mann–Kendal, Abrupt change, Trend.