Abstarct: One of the important issues in hydrogeology is the investigation of the existence or absence of a hydraulic connection between karstic aquifers and adjacent aquifers. In this research, tried to investigate the aforementioned issue in the Do-Qeral Mountain area. The study area is located in Kermanshah Province and 30 km north of Kermanshah city. The Bilevar Plain in the northeast and the Mian-Darband Plain in the southwest of the study area are separated by the limestone hights (Do-Qeral Mountain). The study area is located on the border of two important structural zones of Iran, namely the Zagros and Sanandaj - Sirjan Zones, with the general trend of northwest - southeast. The Main Zagros Fault located in the southern boundary of the study area has a great influence on the structural status of the region. Most of the rock units in the area are limestone rocks of Bisitoun Formation, which forming the hights of Do-Qeral Mountain. Geomorphologic study of the Do-Qeral Mountain shows that there are some karstic features such as karrens, sinkhole, dry valleys, shafts, dissolution spaces, closed depression and caves in this karstic terrain relatively developed karst in the region. In addition, the discharge coefficients of the important karst springs of the region are about 0.02 to 0.05, which confirm karst development in the region. According to the isopotential map, unit hydrograph of the plain and hydrochemical studies, it is observed that the karstic aquifer of Do-Qeral Mountain does not feed alluvial aquifer of Bilevar Plain and there is no hydraulic connection between them. In the Bilevar Plain, the hydraulic gradient is directed to the boundary of alluvial aquifer with limestone, and the values of electrical conductivity and concentrations of main ions are increased toward the boundary. On the contrary, it is obvious that the karstic aquifer reservoir of the Do-Qeral Mountain feeds alluvial aquifers. In the Mian-Darband Plain the hydraulic gradient is from the boundary of alluvium and limestone toward the inside of the plain, in this direction, the values of electrical conductivity and the major ions increase.