The research on the rheology of the composition of nano-CaCO3/PPS of various proportions has been conducted with the high-pressure capillary and the rheological behaviors of 0%, 3%, 5%,10%, 20% and 40% have been observed at the temperature of 290℃. The result shows that when the component of nano-CaCO3 is at the low level, the viscosity of the system is not changed greatly and the rheologcial behavior of the composition system is found to be pseudo-plastic and thus satisfy the power model.