A parametric study for two types .of cable-stayed bridges was carried out. The study considered the harp and the semi-fan systems, Various parameters were considered: different load cases and different cable configurations and numbers . The effect of the previous parameters on the deck moment, deck deflection, deck axial force, and tension forces in cables was investigated. The numerical results indicated that, the deck moment, deck deflection, and deck axial force increase as the number of cables increases, Moreover; the cables tension decreases as the number of cables increases, In general the semi-flan system gives lesser internal forces values than the harp system.