The use of TDR technology to determine the interface level of airwater returns back to the beginning of the 1970's (O'Connor and Dowding, 1999). Using the method for field evaluations was conducted by Dowding and O'Connor (2000). Dowding et al. (1996) compared the use of twisted pair cables and hollow coaxial cables as TDR waveguide. As well, the works performed by the Army Corps of Engineers Waterways Experiment Station, reviewed the use of TDR method to measure the water level (Nicholson et al., 1997). Cataldo et al. (2012, 2012, 2013) conducted a series of experiments to validate the ability of TDR method for detecting water leakage points in underground pipes. Kane and Beck (1996), Mikkelsen (1996), and O'Connor and Dowding (1999) used the Time Domain Reflectometry for monitoring of slide plane. As shown in Fig. 1, rock or soil movement shears the grout and deforms the cable. The electromagnetics pulses are reflected to the pulse transmitter source from the damaged point. The sweep duration and the speed of the pulse in the cable are used to determine the location of the slide plane.In this study, the authors conducted a series of experimental and field studies on RG95/U coaxial cable as the waveguide. They used this technique for monitoring of the ground movements at three potential landslide locations in Darian Dam site.