Poly(phenylene sulfide)/ferrosoferric oxide composites (PPS/Fe3O4) with various loading levels were prepared by melt compounding. The crystallization, thermal, and viscoelastic properties were characterized respectively by the DSC, DMA, TGA and parallel plate rheometer. The results reveal that the well‐dispersed Fe3O4 particle restricts the segmental motion of polymer chain, leading to a remarkable increase of the glass transition temperature and thermal stability of the PPS due to the strong physical association and interactions between particles and matrix. The presence of the Fe3O4 particles, however, can not facilitate crystallization of PPS, because the particles only play the role of inert filler and have no heterogeneous nucleating effect. The crystallization kinetics, as a result, decreases with increasing particles loadings due to the increasing restriction of the chain mobility and high viscosity. In addition, the rheological percolated network of the Fe3O4 particles is very sensitive to the steady shear deformation, and also to the temperature. The network structure is easily broken by the steady shear flow due to the sharply reduced particle–particle interactions. However, the percolation threshold reduces with increase of temperature, because those interactions are temperature‐dependent. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers