The flexural behavior of two kinds of PPS-based composites (carbon and glass fiber woven fabric reinforcements) from 23 to 200 A degrees C was evaluated in terms of load-displacement curves, stiffness, strength and failure mechanisms. With the increase in temperature, the bending stiffness for carbon and glass fiber-reinforced thermoplastic composites decreased by 36.71 and 34.98%, and bending strength deceased by 68.44 and 61.23%, respectively. The failure mode shifted from a brittle fracture to a ductile manner with the increase in temperature owing to the enhanced plasticization of matrix. Dynamic mechanical analysis was performed to characterize the glass transition and decomposition processes of both PPS-based composites and to establish the relationship between temperature and mechanical properties . Compared with the different empirical models, a new simple and stable thermo-mechanical model was proposed to estimate the variation of flexural properties for both thermoplastic composites with temperature.