In this study, for climate zoning and determining the effects of climate change on discharge of Jajrood River Basin, data from 9 available stations in Jajrood River Basin were used. In order to create climatic zones in the Jajrood River Basin, multivariate cluster analysis was used. To validate the data, discriminant analysis was employed. For investigating the effects of temperature and precipitation on discharge of Jajrood River, spatial distribution of discharge, temperature and precipitation parameters were used. According to cluster analysis of the area under study, the basin includes a wet and temperate zone, a dry and temperate zone, a dry and warm zone, and a wet and cold zone. Results of the spatial analysis of climate parameters showed the significant relationship between discharge variations and precipitation, in relation to the other parameters. The spatial distribution of the coefficient of correlation between temperature and discharge indicates that there is low correlation between discharge and temperature. Even in areas where a significant relationship is observed, it is negligible. Generally, it can be said that the fluctuations of the Jajrood Basin are more affected by precipitation than temperature.