This work involves surface analysis by nuclear techniques, which are non-destructive, and computer simulation. The energy analysis method for the nuclear reaction analysis is implemented. Energy spectra are computer simulated and compared to experimental data, giving target composition and concentration profile information. The simulations use, mainly, the target parameterization and the available nuclear data. The method is successfully applied to the determination of uniform concentration profiles of 12 C, along considerable depths, for a thick target, and for a very thin film. Uniform concentration profiles of 16 O are obtained from (d,p) and (d,α) reactions along large depths. A uniform step concentration profile of 18 O in a thick oxide target is also obtained. Elastic scattering is used in the context of a thin Ag film. SEM proves to be a useful technique for checking surface topography.