Using the NOT, WHT and TNG telescopes located at Observatorio del Roque de los Muchachos (Canary Islands, Spain) we have obtained low resolution visible and near infrared spectra of more than 30 Near Earth Asteroids. These observations are part of and observational campaign that started on August 2002 and that also includes photometric and spectrophotometric visible and near infrared observations in telescopes of Observatorio del Teide, in Tenerife. This observational campaign is intended to physically characterize NEO population and to better understand its origin. We present a spectral and a preliminar mineralogical analysis of the reflectance spectra of this sample of asteroids in order to establish their taxonomic classification and to study the mineralogical composition of their surfaces. We use the method of Gaffey et al. (1993) to obtain spectral parameters that are extracted from the spectra of the asteroids and that provide us with information about their surface composition. We also use the Modified Gaussian Model (MGM) method developed by Sunshine et al. (1990) to fit the absorption bands present in the majority of spectra and that are associated to the presence of minerals (mainly silicates), and to obtain information about the physics involved into the different processes that led to the formation of such absorption bands. References Gaffey, M. J., Bell, J. F., Brown, R. H., Burbine, T. H., Piatek, J. L., Reed, K. L. and Chaky, D. A. 1993. Icarus, 106, 573 Sunshine, J. M., Pieters, C. M. and Pratt, S. F. 1990. JGR, 95, B5, 6955