The thermal behavior and phase morphology of binary blends of poly(phenylene sulfide) (PPS) with polycarbonate (PC) have been investigated. Differential scanning calorimetry and dynamic mechanical thermal analysis indicate the blends are immiscible, but the glass transition temperature of PC in the blends was found to be decreased due to the degradation of the PC. The PC degradation was investigated by measuring the molecular weight of PC extracted from the blends. Rheological properties of the blends were also studied using a rheodynamic spectrometer, An inversion of the phase morphology was observed from the scanning electron microscopy and dynamic mechanical thermal analysis. The increase of crystallinity of the PPS in the blends was found from a DSC study.