Nowadays underground structures are very important. Based on observations of engineering; properties during geotechnical construction are an integral part of the design of underground structures. This research presents instrumentation as a tool to assist with these measurement observations, determine the need for modifications to loading or support arrangement. Also apart from above construction control, instrumentation is also indispensable for site investigation, design verification and safety of the structure. Instrumentation used in the construction of tunnels and subways can be implemented in three stagesbefore, during operation and during operation are examined. Metro Railway Tunnels are constructed in populated area and have a more comprehensive instrumentation and monitoring program that additionally includes monitoring of ground conditions, underground water levels, tilt and settlement of nearby buildings or other structures of interest in the vicinity of the tunnel alignment. Instrumentation monitoring for metro railway tunnels includes monitoring of the structures under construction together with the ground, buildings and other facilities within the predicted zone of influence. Furthermore, instrumentation and subway tunnels in and around them increase accuracy of the different layers of the earth and excavation of the surrounding structures and make safety and accuracy. This paper presents the features of sophisticated instrumentation available today for geotechnical monitoring. A wide range of sophistic have been described with their applications ted electronic and mechanical instrumentation with different instrumentation schemes used to meet the requirements of different types of structures.