Global Positioning System (GPS) is a technique of positioning using satellite-based radio-positioning and time transfer systems. Accuracy is the key issue in GPS surveying. Millimeter accuracies can be attained through relative positioning. In relative positioning, a reference station is needed to generate differential GPS corrections and maintenance of reference frames to improve the accuracy of GPS data collected by roving receivers. Hence, the accuracy of the coordinate of the reference station is important to provide high accuracy correction information. In this project, a reference station was established on the roof of the Faculty of Geoinformation Science and Engineering (FKSG), University Technology of Malaysia (UTM), Skudai, Johor Bahru. The objective of this paper is to evaluate the accuracy and reliability of the coordinate of the reference station in relation to MASS stations in Peninsular Malaysia. MASS data set were downloaded from the Department Of Survey and Mapping Malaysia (DSMM) website. Network adjustment was carried out using Trimble Geomatics Office Version 1.50 (TGO).