Composites f(a-Si3N4)/BiSbTe (f ¼ 0, 0.22, 0.44 and 0.88 vol%)were prepared, and their thermoelectric properties were studiedat temperatures from 303 to 483 K. The results indicate thatalthough electrical resistivity increases with increasing a-Si3N4content due to the decrease in both carrier concentrations andcarrier mobility, Seebeck coefficient increases substantially atT < 370 K owing to decrease in carrier concentrations andincrease in scattering parameter. Specially, incorporation ofa-Si3N4 nanoparticles into BiSbTe signicantly reduces thethermal conductivity of composite samples due to enhancedphonon scattering by the nanoparticles and the phase boundaries. As a result, ZT of f(a-Si3N4)/BiSbTe with f ¼ 0.44 vol%reaches 1.20 at 303 K (which is larger than that (1.01) of BiSbTematrix in the present study), and specically its maximum ZTreaches 1.38 at 383 K, which is round 8% larger than that (1.28)of BiSbTe matrix. Present results suggest that incorporation ofamorphous nanoparticles into thermoelectric materials, suchas BiSbTe-based alloys, be an effective way to enhancing theirthermoelectric performance