The flows in hydrodynamic torque converter are extremely unsteady and complicated 3D viscous and incompressible turbulences. The unsteady computational fluid dynamics (CFD) model of hydraulic torque converter (HTC) is established to study the unsteady flow field in the pump of the HTC due to the pump/stator and pump/turbine interaction, at the pump rotating speed of 800rpm, and the turbine/pump speed ratio of 0.6. The time-averaged CFD results obtained are compared with experimental data gathered using laser Doppler anemometry (LDA). The basic phenomena of the complex and highly unsteady flow inside the pump is presented and analyzed in detail. The results show that the upstream propagation influence of the stator on the pump flow field is stranger than that of the turbine, the effect of the stator on the pump is mainly on the inlet-plane to the mid-plane, the effect of the turbine on the pump is mainly on the low speed area from the mid-plane to outlet-plane.