Paper deals with experimental and numerical works of drag force measurements over a 80 mm diameter sphere. Test models were suspended in a 300mm x 300mm cross sectional vertical shock tube. Unsteady drag forces were measured directly with accelerometers installed inside the test models. Flow visualizations of individual shock/model interactions were visualized quantitatively with double exposure holographic interferometry and sequentially with high-speed video recording. Shock Mach number was 1.2 in air. Measured unsteady drag forces of individual bodies were compared with numerical results by solving the Euler equations and the Navier-Stokes equations with meshes of level four refinements. In addition to appearance of peak drag forces, negative drag forces appear when the transmitting shocks merge at bodies rear stagnation points.