Abstarct: Water resources existing in igneous and mextamorphic hardrocks, due to the relatively low supply and discharge them less than other calcareous water and alluvial interest. However, hardrocks in dry areas and also in areas that are lacking in major aquifers, are important. in this research, Mahabad rhyolitic hardrock Infracambrian old which is located at 20 km East, was selected to study its hydrochemical groundwater resources. During the two-stage sampling of water resources in Mahabad rhyolitic 15 water samples and 22 water samples in September of 2015 taken in April and the main ions and silica molecular components were measured The concentration of heavy mextals (aluminum, iron, arsenic, barium, nickel, lead, strontium and zinc) in 11 samples was determined in the August 2015. According to the results mean molecular component silica in the rhyolitic groundwater resources in Mahabad 18/36 mg per liter respectively.Spatial variation of physicochemical parameters of water resources in Mahabad rhyolits increasing amounts of EC, pH, SiO2 and temperature of water resources in the area along the flow path from the highlands to the output shows. The main spatial variation of ions, especially sodium and magnesium cations significant increase in the flow of the show. type of groundwater changed from Ca-HCO3 in the wet season to the Ca-Na-HCO3 in dry season. This probably is the relationship with cation exchange and minerals dissolution. Time changes physicochemical parameters of rhyolitic water resources as well as increasing amounts of EC, SiO2, ion content and temperature of the water resources of the wet season to the dry season shows. The results of the analysis of heavy mextals also suggests that the concentration of heavy mextals other than lead (pb) lower than the standard World Health Organization (WHO) respectively. High concentrations of lead (pb) with an average of 34/83 micrograms per liter, possibly due to shale formations in Mahabad rhyolite. Barium (Ba) with sulfate (SO4) positive correlation, and most likely is the result of the dissolution of the mineral barite.