Groundwater contamination is a serious problem facing the countries. Because groundwater is vulnerable to contamination from a variety of sources, and, once contaminated, it is very difficult to restore to its original quality. The main objective of this study was evaluation of groundwater quality in Shahrekord aquifer and finding the source of the groundwater contamination. Some of the chemical parameters such as Cation, Anion, Electrical Conductivity (EC), Total Hardness (TH) and Total Dissolved Solids (TDS) were measured in four times including spring and autumn of two years. The results show that the chemical contaminant concentration in North-Western part (NWP) of the aquifer was lower than Southern part (SP). Bicarbonate in the Anions and Calcium in the Cations has the maximum value. However they are lower than the standard limits. The TH in the wells varies from 150 [1]to 300 (mg/lit/CaCo3). The water quality is classified in hard water category base on TH. The result shows that there wasn’t considerable difference in TH and TDS values on spring and autumn seasons. The maximum nitrate concentration was almost 37 mg/lit in the northern parts. The result shows that TH and TDS in the southern parts and Nitrate concentration in the northern parts were maximum values concentration. This subject shows that the source of these contaminants is different. The agricultural lands produce Nitrate contamination and the urban wastewater is source of chemical concentration and TDS