Melt blends of poly(phenylene oxide)(PPO) with glass fiber reinforced syndiotactic polystyrene(GFRsPS) were prepared using a single screw extruder. DSC and dynamic mechanical measurements indicate that the PPO/GFRsPS blends are miscible in amorphous state as shown by the existence of a single T-g whose values are blend composition-dependent. From the mechanical test results, it is shown that the tensile and flexural modulus increase, but the tensile and flexural strength do not improve as the GFRsPS content increases. An increase in the melt how index (MFI) as GFRsPS contents increase implies that the processing problem of neat PPO is improved.