The measurement of ground reaction force (GRF) is important in biomechanical analysis for clinical gait assessment and gait research. The GRF measured by the force plate, along with the gravity, are the only significant external forces acting on the body during gait. The purpose of this study is to show the effects of walking speed on vertical ground reaction force (VGRF) F z using Kistler quartz force platform embedded on the floor. Since considerable differences in the gait of normal subjects arises due to ‘constrained’ walking, so subject are made to walk with their self selected walking speed in the walkway. Vertical component of the GRF was analysed from the recorded data using Bioware software. It was clearly observed that with increasing walking speed VGRF increased at F z 1 and F z 3 whereas decreased at F z 2 .