In recent years, rainfall reduction and the occurrence of drought phenomenon has exacerbated the quality changes of Zeydon plain groundwater. Therefore, this study was carried out to evaluate the rainfall fluctuations on the quality of groundwater and to improve the utilization management and optimal utilization of groundwater resources. In this study, sampling of the water resources of Zeydon plain was performed in two stages in order to study the quality of Zeydon plain groundwater and assess the role of rainfall in the qualitative results of these resources. First, 10 samples of water wells in April 2012 as the rainy season and then 10 samples were selected in September 2012 as the dry season. Finally, it was concluded that in terms of quality along with the rainfall, the concentration of groundwater ions and salts in this plain is increased, which means that during rainy years along with the rainfall, the quality of the aquifer groundwater is getting worse. Based on the obtained reviews, the increase in the concentration of ions during rainfall in Zeydon aquifer is due to the presence of Gachsaran, Mishan and Aghajari formations in the north of the plain and the high groundwater level in some areas, especially in the center of the plain.