In this study, statistical trend analysis of climate parameter of total precipitation, number of rain days, mean relative humidity, mean temperature, mean minimum and maximum temperatures in both monthly and annual scale was in Sabzevar. For this purpose, the Mann- Kendall test for detection how trend and sen’s estimator of slope for magnitude or slope of trend in time series for 1961 until 2011 were used. In the time series, the time series of total precipitation in April, May, June, October and January shows a negative trend for precipitation, although not statistically significant, but the dry climate of the region, the occurrence of a negative trend in the peak months increased crop water requirement and the increase temperature parameter is important. Based on test statistics Mann - Kendal and graphical Mann - Kendall in the time series of temperature, mean minimum temperature of the increasing trend towards longer time series of temperature is evident. Results of this study, with the findings of some research about some parts of Iran that Rising temperatures and reduced rainfall have confirmed the almost consistent. Other notable points, the significant increase in the average minimum temperature is. The annual average temperature scale, the average minimum and average maximum temperature the increase in Confidence interval 99/99 percent respectively. Mann- Kendall graphic chart is drawn for the annual time series a weak negative trend in total annual precipitation and mean relative humidity especially in recent decade’s shows in Sabzevar. Keywords: Trend, Mann-Kendall, Method Sen’s Estimator of Slope, climate parameter, Sabzevar.
