Abstract: Determining the concentration of the radon 222 in the groundwater, determine the relationship between the radon concentrations and the water temperature and the water electrical conductivity are the main purposes of this study. The Jordan Valley classified as high radiant area because of the Jordan Valley contains a high active faults and the strata are high fractured. The main shallow aquifer in the study area consists of gravel and the second shallow aquifer consists of limestone, while the deep aquifer consists of sandstone. A total of 53 groundwater samples from the wells and springs in the study area were collected in order to achieve these objectives. The well samples were collected from hand pumps and tube wells covering different hydrogeological areas in the study area. The samples were analysed by using RAD7 instrument. The major physical-chemical parameters have been measured directly during sampling with a portable HANNA instrument with a multi-parameter probe (T, pH and EC). The radon-222 content in water may serve as a useful tracer for several hydrological processes. To understand the factors that control the occurrence of radon in groundwater of Jordan valley, Radon variation in tube wells and hand pumps varies from minimum amount 0.28±1.5 to the maximum amount of 44.31±3.2 Bq L-1 with an average of 6.2±2.5 Bq L-1. A significant positive correlation between radon concentration and water temperature was observed in areas suggesting that radon concentration increases with temperature increasing and negative correlations between radon concentrations and the water salinity.