The flexural performance of the beams reinforced with both non-prestressed bars and prestressed bonded FRP bars was theoretically analyzed. Both the CFRP bar and the AFRP bar were taken as the representatives in the study. Correlativity of two kinds of balanced relative depth of compressive area, respectively corresponding to the yield of steel bar and to the rupture of FRP bar, was investigated. Therefore the influence of performance parameters of FRP on the flexural failure modes was analyzed. The results indicate that failure modes and two kinds of balanced relative depth of compressive area are with direct correlation, and the latter is directly influenced by the performance of the FRP bars. Adopting the short-term performance parameters or the long-term performance parameters, which considers the environmental factor, creep fracture factor, relaxation factor and materials coefficiency, would have different results. Failure mode I is the ideal one, while the others should be avoided. Prestressed control stress of CFRP bars with low-ductility should not be too high, otherwise the rupture of CFRP bars will happen before the yield of steel bars.