Hybrid composite cables on the base of steel, GFRP, CFRP and Vectran, which differ by the components and volume fractions, were considered as materials of suspension and contour cables for a prestressed saddleshaped cable roof with the dimensions 50x50 m. The behaviours of hybrid composite cable were investigated analytically and by experiment. Simplified method for prediction of mechanical properties of hybrid composite cables was suggested and checked by the experiment. Opportunity to decrease the displacements and dead weight of composite saddle-shaped cable roof with the dimensions 50x50 m by using of hybrid composite cables with steel component for suspension and contour cables was investigated.