Sinai Peninsula is an important part in Egypt, economically, historically, securitally and strategically. Therefore, the development of Sinai is one of the main aims for the Egyptians. The development of Sinai requires a lot of money, efforts, and time while Sinai Peninsula lies in unstable area, from the seismic point of view. So, following the Crustal movement of that area, is an important matter, for planning, construction, security of the projects and inhabitants. A geodetic network was initiated in Sinai in 1994 consisting of 12 stations. An Earthquake occurred in Sinai in 1995. The network was successively observed in the years 1994, 1996, 1998, and 1999. This research is made for studying the effect of the earthquake on the crust and its behaviour, along four years after the occurrence of the earthquake. GPS dual frequency receivers were used in observing the network. The results showed considerable horizontal and vertical movements at some places in Sinai because of the earthquake. The results showed also that, the crust was retaining to its former position with time.