A new technique based on the use of highly concentrated sunlight in cancer and tumors treatment which gives the same changes in biological tissue as conventional laser surgery is suggested in this thesis. A Schmidt Cassegrainin arrangment is used in design the optical solar system. It consists of a paraboliadal dish suggested to concentrate the solar radiation on a secondary flat mirror which directs the light into a fused silica optical fiber cable used to carry the concentrated solar beam from the concentrating system to the operation room. The parabolic reflector dish rim half angle has been chosen to be 45° to realize high flux and high efficiency. It must be coated with silver layer then a very thin protective layer of silica as any standard mirror. Microsoft Excel program (2007) has been used to study the effect of changing the rim half angle of the parabolic dish on the solar concentrator design parameters, to choose the best dimensions in order to achieve maximum efficiency. MATLAB program (version 7.00) has been used to calculate the diameter of the primary parabolic mirror and the diameter of the secondary flat mirror and its recession from the fiber tips by two design procedure. The first procedure of these calculations is based on the choosing of the optical fiber diameter and the second procedure is based on the choosing of the distal end diameter of the optical fiber. The last suggested of solar system size after the two procedures of calculations is chosen by considering the second procedure that based on distal end diameter of the optical fiber. The most often used fiber distal diameter in surgery is 0.6mm. Accordingly, the diameter of the primary parabolic mirror is 180mm. It's focal length of 108.64mm. The small secondary mirror is perfectly flat of 10.5mm in diameter and its recession from the fiber tip is 5.27mm. Another MATLAB program has been written to find the suitable numerical aperture for the optical fiber of the concentrator system at maximum efficiency. It is found to be 0.7 theoretically and the nearest available value of NA for fused silica fiber was 0.66. Fused silica optical fiber of 1mm for core diameter was chosen because of its ability to carry the high degree of temperature. MATLAB programs were used to calculate and graph the change of relative transmission according to the incidence angle for all of types of optical fibers that have a core of fused silica with refractive index 1.45. The programs are presented to exhibit the light leakage within optical fiber nominal NA. It is found that this optical system could deliver a flux density as high as 73 Wmm-2 for contact surgery and 32Wmm-2 for noncontact surgery. OptiCAD focus software program (version 5.00) is used to demonstrate and investigate a geometrical ray-trace of a band of the sun light through the suggested solar system.