Recently, there has been increasing interest in developing the reconstruction system of computed tomographic (CT) toward increasing the system performance and image enhancement to prevent the object from exposing the radiation dose for more time; as a result the effect of these radiations may cause damage in health of the human. This thesis presents the implementation of reconstruction algorithm of CT image using an analytical method called filtered back projection (FBP) for the two geometries parallel beam projection, and fan beam projection. This work consist three main parts. In first part, many numbers of projections are obtained from the input test image called Shepp Logan phantom using the Radon transform. The second part, reconstruct the image from parallel beam projection to reduces the reconstruction time of fan beam projection using rebining algorithm, it’s used to rearrange fan beam projections to parallel beam projections to reduce the complexity of reconstruction instead of using direct fan beam reconstruction equations In the third part, filter the projections using Ram Lak filter and Hann window for image enhancement and then back projection summation to form the reconstructed image. The computer program has been designed, written and implemented in our work using MATLAB for the two methods of geometry parallel beam, and fan beam projections. This made the result very good for reconstruction two dimensions image from its projection in Computerized Tomography scanner.