The pollutants of ground water resources are divided in to two groups, natural and human factors. The purpose of this research is to study Silakhor plain hydrochemically and its pollutants. Silakhor plain is about 1100 square kilometer located in the west of Iran and north east of Lorestan province. In this research, the quality of surface and ground waters of Silakhor plain and also the effective factors on the quality of this water have been studied. In order to do this, in two dry season. (October, 2014) and wet season (May, 2015) 32 and 20 samples of Silakhors’ underground and surface waters were taken. Parameters such as electronic conductivity (EC) and acidity (PH) were measured in their own taken places. Then, in order to study the effect of geological factors on the quality of the regions’ waters, the density of the main anions and cations of the plains’ water resources were studied and the results were compared with the universal standards world’s amounts. After that, in order to study the effect of agricultural activities, the density of nitrate and phosphate and to study the effect of industrial activities the density of heavy elements was studied. The result of this research shows that just concentration of Boron in three samples was higher than the universal standards and it is due to the adjacency of these places to stonecutting workplaces. It seems that it is these stone cuttings which have caused an increase in concentration of Boron in the samples.