The influence of the electron and hole traps, introduced by electron irradiation, on the drift mobility and carrier concentration profiles of the GaAs epitaxial layer structure was investigated. The DLTS and DLOS measurements indicated three electron traps and four hole traps identified to already known. The mobility profile was analyzed as a function of temperature T #62; 175 K in terms of lattice scattering (acoustical and polar optical phonons) and scattering on ionized impurities and space charge (clusters) produced mainly by irradiation.