Deformation pattern around the central part of the Great Sumatran Fault has been determined by a geodetic survey. First geodetic measurements were carried out in the Singkarak Lake-Padang area in August 1991. The second geodetic survey reoccupied the stations in September 1994. No major or moderate seismic event (M> or =5) has occurred in this area between the two measurements. As no significant relative displacement was observed on both sides of the fault trace, and as about 90 mm displacement affects the far field points, we may emphasize that the fault segment is locked and that consequently it has a seismic behaviour. In addition, slip rate calculated with geodetic data from far field points (27.5+ or -2.5 mm/yr) is similar with the geologically determined long term slip rate (23+ or -2 mm/yr).