Abstarct: Geophysical surveys comprising of resistivity and refraction seismic methods in Brujen area of Chahar Mahal Bakhtiari Province have been carried out to recognize subsurface laxyers in a dam site. Resistivity sounding surveys using schlumberger array have been carried out in some locations on 6 lines along the river with a northwest-southeast trend in the area. Then, interpretation of the resistivity sounding data has been made using standard curves and Res2dinv software package in order to determine the geological laxyers in the study area. Refraction seismic surveys using conventional seismic arrays along 5 profiles perpendicular to the resistivity sounding lines have been carried out using 7 shots and 24 geophones with a 15 m spacing, and baxsed on of travel times of seismic waves, received by the geophones, the subsurface geological laxyers in study area have been recognized. For 2-D modeling of seismic data, Winsism 10 software was used. The results of the seismic and resistivity modeling indicate that the subsurface laxyers in the study area are composed of two major laxyers. First laxyer, that is alluvium, consists of sediments and weathered rock and the second laxyer is the bedrock. Thickness of alluvium is variable between 0 to 30 m. The thickness of the alluvium is between 20 to 30 m along the river and also is between 20 to 30 m in the alluvial fan located in the western part of the area. In north, southeast and southwest of the area with limestone high elevations, the thickness of the alluvium is between 0 to 10 m. The bedrock is of the limestone type. It has a high resistivity with low fracturing and low weathering in high elevations. However, in some cases, the resistivity of the bedrock at a great depth decreases that is because of water-filling cavities and formation change. Along the river, because of the fractures due to faulting and weathering, the limestone bedrock has also a low resistivity.