Going forward towards developing and improving renewable energies in Algeria is one of the main objectives of this study, especially, solar energy that is an exceptional and continuous source of energy. Algerian Sahara has a large area suitable for agriculture, but not connected to the electricity network. Therefore, the construction of solar power plants based on the solar energy concentration has been proposed for the electricity production, which is exploited in the rest of the economic sector of the Algerian state. Through the study conducted under real weather data for the day March 16th, 2018, an optical characterization of a solar power plant of parabolic trough concentrator has been convoyed in El-Oued region, Algeria. The geometrical and the optical characteristics of studied solar collector have been determined, such as the optical efficiency, the local concentration ratio, the cosine effect of the incidence angle, the optical losses at the ends of the receiver tube, the shading effect, the blocking effect, and the coefficient of incidence angle modifier and intercept factor. MATLAB code has been used as a program for numerical programming. Of the most important results obtained, it was found that the optical efficiency has exceeded 77.22 %. As for the local concentration ratio, its maximum value is equal to 116.30 in the lower part of the receiver tube at the peripheral receiver angles “β=91° and 269°", while the minimum values of this important coefficient were recorded at the top of the receiver tube.