In this paper, we propose the optimal design scheme for designing an SUGV (Small Unmanned Ground Vehicle) for the purpose of surveillance and reconnaissance in urban and rough terrain, tunnels, sewers, and caves. In general, an SUGV for military operations must be light-weight and small in size to attain portability, and must be able to overcome a variety of obstacles including stairs, curbs, and ramps in urban terrain. Consequently, we propose the optimal design scheme to find the optimal size and optimal actuation system of such an SUGV. The scheme is composed of three parts. The first is to find the optimal body length of the SUGV through estimating the CG point moving path in geometrical coordination when climbing stairs. The second is to find material having the required static friction coefficient by estimating the required traction force and wheel moment. The third is to find the actuation load by estimating the wheel load while it climbs up a ramp with ${ heta}$. From this scheme, we find an optimally designed SUGV for the purposes of military operations. In this paper, to prove the efficiency of the proposed design scheme, we build an SUGV and experiment its mobility performance. The experimental results demonstrate its stair climbing performance on 20cm high and 40degree inclined ramps. The SUGV weighs 21kg and has a minimum body length of 625mm.