Climate change is currently one of the most important environmental challenges in the world today. In recent years, climatic fluctuations, especially its impact on the Earth's water resources, has received much attention. This study seeks to investigate and detect fluctuations and possible trends in jarahi river discharge, using nonparametric trend analysis models including two methods of non-parametric Mann-Kendall test and Sen’s Slop Estimator model during last 52 years (1347-1397). After revealing the presence or absence of the trend, the relationship between the flow time trend of the mentioned rivers with the precipitation values and the surface temperature of the basin is investigated and analyzed. The results indicated that during the winter months of January to March, the monthly Jarahi River discharge had a significant decreasing trend. The decreasing trend of Jarahi River discharge in these months has been between 1 to 3.5 cubic meters per second. In the autumn months, as in the summer season, a decreasing trend was observed in the Jarahi River discharge and as correlation matrix showed, in the two seasons of autumn and winter, a significant and direct relationship was observed between the precipitation values of these seasons and the seasonal discharge of Jarahi River. In winter, the correlation coefficient between the discharge of Jarahi River and rainfall recorded in Kegar and Mashrageh stations was equal to 0.55%, which is a direct and significant relationship between discharge and rainfall in this season. Shown. The correlation coefficient between the rainfall of the jarahi basin and the recorded discharge of the jarahi river was equal to 0.30, which was significant at the confidence level of 0.95 (P_value = 0.05) (Sig = 0.011).